A man rides a bike along a straight road at a constant speed for 5 minmin, then has a flat tire. He stops for 5 minmin to repair the flat, but then realizes he cannot fix it. He continues his journey by walking the rest of the way at a constant speed, which takes him another 10 minmin.  Select a correct motion diagram of the man for the entire motion described here.

A jogger running east at a steady pace suddenly develops a cramp. He is lucky: A westbound bus is sitting at a bus stop just ahead. He gets on the bus and enjoys a quick ride home. Use the particle model to draw a motion diagram of the jogger for the entire motion described here. Number the dots in order, starting with zero.

What is Sue's position xx if her home is the origin? Assume the positive direction is to the right.

Express your answer using one significant figure.

What is Sue's position xx if the cinema is the origin? Assume the positive direction is to the right.

Express your answer using one significant figure.

An object moves along the x axis during four separate trials. Graphs of position versus time for each trial (with the same scales on each axis) are shown in the figure. During which trial or trials is the object's velocity not constant?

An object moves along the x axis during four separate trials. Graphs of position versus time for each trial (with the same scales on each axis) are shown in the figure. During which trial or trials is the magnitude of the average velocity the largest?

An elevator is moving downward when someone presses the emergency stop button. The elevator comes to rest a short time later. After the button has been pressed but before the elevator has stopped, the velocity of the elevator is _____, and the acceleration of the elevator is _____.

A child throws a baseball directly upward. Immediately after the ball leaves the child's hand, the velocity of the ball is ____, and the acceleration of the ball is ____.

A child throws a baseball directly upward. At the very top of the ball's motion (i.e. the point of maximum height), the velocity of the ball is ____, and the acceleration of the ball is ____.

The table below shows the x coordinate of a moving object. The position is tabulated at one-second intervals. The x coordinate is indicated below each time.

time (s) 0 1 2 3 4 5 6 7 8 9

x (m) 0 1 4 9 16 24 32 40 46 48

Which graph (Figure 1) best represents the function x(t)x(t), describing the object's position vs. time?

The table below shows the x coordinate of a moving object. The position is tabulated at one-second intervals. The x coordinate is indicated below each time.

time (s) 0 1 2 3 4 5 6 7 8 9

x (m) 0 1 4 9 16 24 32 40 46 48

Which of the following graphs (Figure 2) best represents the function v(t)v(t), describing the object's velocity as a function of time?

The table below shows the x coordinate of a moving object. The position is tabulated at one-second intervals. The x coordinate is indicated below each time.

time (s) 0 1 2 3 4 5 6 7 8 9

x (m) 0 1 4 9 16 24 32 40 46 48

Which of the following graphs (Figure 3) best represents the function a(t)a(t), describing the acceleration of this object?

(Figure 1) shows the velocity graph of a bicycle. Choose the correct bicycle's acceleration graph for the interval 0s ≤ t ≤ 4s.

In a ballistocardiograph, a patient lies on an extremely low friction horizontal table. At each heartbeat, a volume of blood is accelerated by the heart toward the head along the ascending aorta. In response, the patient's body recoils in the opposite direction. This motion is detected by sensitive accelerometers attached to the table. (The table is then brought to rest and returned to equilibrium before the next heartbeat.) A graph of acceleration of the table versus time, termed a ballistocardiogram, is generated. Based on these measurements, the acceleration of the blood ejected by the heart can be determined. Patients with low blood accelerations generally have weakened heart muscles.

A sketch of a single cycle of a ballistocardiogram is given in the figure. (Figure 1). The units of the graph are arbitrary and linear for both time,tt, and acceleration, aa. At what time (in the arbitrary time units of the graph) is the speed of the table (and hence the speed of the blood in the opposite direction) a maximum?

The slope at a point on a position-versus-time graph of an object is the __________.

Which of the following is an example of uniform motion?

The area under a velocity-versus-time graph of an object is __________.

If an object is speeding up, __________.

A 1-pound ball and a 100-pound ball are dropped from a height of 10 feet at the same time. In the absence of air resistance, __________.

A student at the top of a building of height h throws ball A straight upward with speed v0 and throws ball B straight downward with the same initial speed. Compare the ball's accelerations, both direction and magnitude, immediately after they leave her hand. Is one acceleration larger than the other? Or are the magnitudes equal?

A student at the top of a building of height h throws ball A straight upward with speed v0 and throws ball B straight downward with the same initial speed. Compare the final speeds of the balls as they reach the ground.

A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

When is the average velocity of an object equal to the instantaneous velocity?

Which of the following quantities has units of a velocity? (There could be more than one correct choice.) Check all that apply.

An object is moving with constant non-zero acceleration in the +x direction. The position versus time graph of this object is

A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock?

The area under a curve in a velocity versus time graph gives

If the velocity versus time graph of an object is a horizontal line, the object is

An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is

The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure. The two vehicles are initially alongside each other at time t = 0. At time T, what is true of the distances traveled by the vehicles since time t = 0?

From the edge of a roof top you toss a green ball upwards with initial speed v₀ and a blue ball downwards with the same initial speed. Air resistance is negligible. When they reach the ground below

A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground?

A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct?

Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct?

A ball is thrown downward in the absence of air resistance. After it has been released, which statement(s) concerning its acceleration is correct? (There could be more than one correct choice.)

The motion of a particle is described in the velocity vs. time graph shown in the figure. Over the nine-second interval shown, we can say that the speed of the particle

If the position versus time graph of an object is a horizontal line, the object is

Under what condition is average velocity equal to the average of the object's initial and final velocity?

Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object.

Which of the following situations is impossible?

The slope of a velocity versus time graph gives

The slope of a position versus time graph gives

What is the xx component of A?

What is the y component of A?

What is the y component of B→?

What is the x component of C→?

What is true about B and D?

Alex, a mountaineer, must make it across a wide crevasse. Alex runs horizontally off the edge and successfully makes it to the other side of the crevasse, which is below the point from which he takes off, as shown in (Figure 1). At the instant he leaves the ground at the edge of the crevasse, Alex's x velocity is ____ and y velocity is ____.

Alex, a mountaineer, must make it across a wide crevasse. Alex runs horizontally off the edge and successfully makes it to the other side of the crevasse, which is below the point from which he takes off, as shown in (Figure 1). The instant before he safely lands on the other side of the crevasse, Alex's x velocity is ____ and y velocity is ____.

Alex, a mountaineer, must make it across a wide crevasse. Alex runs horizontally off the edge and successfully makes it to the other side of the crevasse, which is below the point from which he takes off, as shown in (Figure 1). The instant after it leaves the player's hands, the ball's x velocity is ____ and y velocity is _____.

Alex, a mountaineer, must make it across a wide crevasse. Alex runs horizontally off the edge and successfully makes it to the other side of the crevasse, which is below the point from which he takes off, as shown in (Figure 1). At the ball's maximum height, the ball's x velocity is ____ and y velocity is ____.

When setting up projectile motion questions, which of the following characteristics of projectile motion are important to keep in mind?

Check all that apply.

A ball thrown horizontally with speed v = 27.0 m/s travels a horizontal distance of d = 54.0 m before hitting the ground. Which diagram represents an accurate visual overview of the ball?

The speed at which the package hits the ground is really fast! If a package hits the ground at such a speed, it can be crushed and also cause some serious damage on the ground. Which of the following would help decrease the speed with which the package hits the ground?

A cannon is fired from the top of a cliff as shown in the figure. Ignore drag (air friction) for this question. Take H as the height of the cliff. (Figure 1). Which of the paths would the cannonball most likely follow if the cannon barrel is horizontal?

A cannon is fired from the top of a cliff as shown in the figure. Ignore drag (air friction) for this question. Take H as the height of the cliff. (Figure 1). Now the cannon is pointed straight up and fired. (This procedure is not recommended!) Under the conditions already stated (drag is to be ignored) which of the following correctly describes the acceleration of the ball?

Two stones are launched from the top of a tall building. One stone is thrown in a direction 15.0 ∘ above the horizontal with a speed of 20.0 m/s ; the other is thrown in a direction 15.0 ∘ below the horizontal with the same speed. Which stone spends more time in the air? (Neglect air resistance.)

Two stones are launched from the top of a tall building. One stone is thrown in a direction 15.0 ∘ above the horizontal with a speed of 20.0 m/s ; the other is thrown in a direction 15.0 ∘ below the horizontal with the same speed. Which stone lands farther away from the building? (Neglect air resistance.)

How do the speeds v0, v1, and v2 (at times t0, t1, and t2) compare?

A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

Consider two vectors  A and  B shown in the figure. The difference A−B is best illustrated by

A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will

For a projectile, which of the following quantities are constant during the flight: x, y, vx, vy, v, ax, ay?Check all that apply.

Which of the quantities are zero throughout the flight (projectile)?

Check all that apply.

You are trying to cross a river that flows toward the south with a strong current. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should head your motorboat

If you kick a football, at what angle to the ground should you kick the ball for the maximum range - that is, the greatest distance down the field?

At what angle to the ground should you kick the ball for the maximum "hang time" - that is, the maximum time in the air?

For general projectile motion with no air resistance, the horizontal component of a projectile's velocity

Two perpendicular vectors, A and B, are added together giving vector C. If the magnitudes of both vectors A and B are doubled without changing their directions, the magnitude of vector C will

If a vector A→ has components Ax>0, and Ay<0, then the angle that this vector makes with the positive x-axis must be in the range

For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration

If a vector A has components Ax<0, and Ay>0, then the angle that this vector makes with the positive x-axis must be in the range

A ball is fired from a cannon at point 1 and follows the trajectory shown in (Figure 1). Air resistance may be neglected. Five possible vectors are also shown in the figure; the letter E represents the zero vector. Which vector best represents the ball's velocity at position 2?

A ball is fired from a cannon at point 1 and follows the trajectory shown in (Figure 1). Air resistance may be neglected. Five possible vectors are also shown in the figure; the letter E represents the zero vector. Which vector best represents the ball's acceleration at position 2?

A ball is fired from a cannon at point 1 and follows the trajectory shown in (Figure 1). Air resistance may be neglected. Five possible vectors are also shown in the figure; the letter E represents the zero vector. Which vector best represents the ball's velocity at position 3?

A ball is fired from a cannon at point 1 and follows the trajectory shown in (Figure 1). Air resistance may be neglected. Five possible vectors are also shown in the figure; the letter E represents the zero vector. Which vector best represents the ball's acceleration at position 3?

Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are added together, the magnitude of the sum

Consider two vectors A and B shown in the figure. The difference B−A is best illustrated by

Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance?

Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30° above the horizontal. Which of the following statements are true about just as the snowballs reach the ground below? (There could be more than one correct choice.)

A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's motion are true just before it hits the ground?

A ball is thrown horizontally from the top of a tower at the same instant that a stone is dropped vertically. Which object is traveling faster when it hits the level ground below if neither of them experiences any air resistance?

Determine the object of interest for the situation described in the problem introduction. For this situation you should draw a free-body diagram for

Identify the forces acting on the object of interest. From the list below, select the forces that act on the piano.

Check all that apply.

Select the choice that best matches the free-body diagram you have drawn for the piano.

Chadwick now needs to push the piano up a ramp and into a moving van. (Figure 2) The piano slides up the ramp without friction. Is Chadwick strong enough to push the piano up the ramp alone or must he get help? To solve this problem you should start by drawing a free-body diagram. Determine the object of interest for this situation. For this situation, you should draw a free-body diagram for

Chadwick now needs to push the piano up a ramp and into a moving van. (Figure 2) The piano slides up the ramp without friction. Is Chadwick strong enough to push the piano up the ramp alone or must he get help? To solve this problem you should start by drawing a free-body diagram. Which diagram accurately represents the free-body diagram for the piano?

As the child rides in the seat, his/her head and back rest against the padded back of the seat. If the car is brought to a rapid stop (as in a head-on collision) the child will continue to move ____ at the before-crash speed until he/she hits something.

In a head-on collision, an infant is much safer in a child safety seat when the seat is installed facing the rear of the car. The object hit is the back of the seat (supporting the entire back and head) which is padded and as a result the force ____ to the maximum value over a time interval.

In a head-on collision, an infant is much safer in a child safety seat when the seat is installed facing the rear of the car. Granted this time interval may be ____ but that is considerably better than instantaneous. Also since the head is supported, there will be ____.

Consider a book resting on a horizontal table. Which object exerts a downward force on the book?

Consider a book resting on a horizontal table. The downward force acting on the book is __________.

Consider a book resting on a horizontal table. What is the downward force acting on the book called?

Consider a book resting on a horizontal table. Which object exerts an upward force on the book?

Consider a book resting on a horizontal table. The upward force acting on the book is __________.

Consider a book resting on a horizontal table. What is the upward force acting on the book called?

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. Which object exerts a force on the block that is directed toward the right?

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. The force acting on the block and directed to the right is __________.

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. What is the force acting on the block and directed to the right called?

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. Which object exerts a force on the block that is directed toward the left?

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. The force acting on the block and directed to the left is __________.

A string is attached to a heavy block. The string is used to pull the block to the right along a rough horizontal table. What is the force acting on the block and directed to the left called?

The same block is placed on the same rough table. However, this time, the string is disconnected and the block is given a quick push to the right. The block slides to the right and eventually stops. How many forces are acting on the block in the horizontal direction?

The same block is placed on the same rough table. However, this time, the string is disconnected and the block is given a quick push to the right. The block slides to the right and eventually stops. What is the force acting on the block that is directed to the left called?

A mountain climber is hanging from a vertical rope, far above the ground and far from the rock face. The rope is vertical. Identify the forces on the mountain climber.

A baseball player is sliding into second base. Identify the forces on the baseball player.

A jet plane is speeding down the runway during takeoff. Air resistance is not negligible. Identify the forces on the jet.

What is the direction of the net force acting on the object at position A?

What is the direction of the net force acting on the object at position B?

What is the direction of the net force acting on the object at position C?

Consider the following situations:

1. a. A car is moving along a straight road at a constant speed.

2. b. A car is moving along a straight road while slowing down.

3. c. A car is moving along a straight road while speeding up.

4. d. A hockey puck slides along a smooth (i.e., frictionless) icy surface.

5. e. A hockey puck slides along a rough concrete surface.

6. f. A rock is thrown horizontally; air resistance is negligible.

7. g. A rock is thrown horizontally; air resistance is substantial.

8. h. A rock is dropped vertically; air resistance is negligible.

9. i. A rock is dropped vertically; air resistance is substantial.

10. Which of these situations describe the motion shown in the motion diagram at point A?

    Select all that apply.

An astronaut is taking a space walk near the shuttle when her safety tether breaks. What should the astronaut do to get back to the shuttle?

Assuming that the astronaut can throw any tool with the same force, what tool should be thrown to get back to the shuttle as quickly as possible? You should consider how much mass is left behind as the object is thrown as well as the mass of the object itself.

You look up from your textbook and observe a spider, motionless above you, suspended from a strand of spider silk attached to the ceiling. You distract yourself by identifying the forces acting on the spider. What are they?

Check all that apply.

A skier is sliding down a 15∘ slope. Friction is not negligible. Identify the forces on the skier.

Check all that apply.

A falcon is hovering above the ground, then suddenly pulls in its wings and begins to fall toward the ground. Air resistance is not negligible. Identify the forces on the falcon.

Check all that apply.

A constant force applied to object A causes it to accelerate at 6 m/s2 . The same force applied to object B causes an acceleration of 3 m/s2. Applied to object C, it causes an acceleration of 8 m/s2. Which object has the largest mass?

A constant force applied to object A causes it to accelerate at 6 m/s2 . The same force applied to object B causes an acceleration of 3 m/s2. Applied to object C, it causes an acceleration of 8 m/s2. Which object has the smallest mass?

A constant force applied to object A causes it to accelerate at 6 m/s2 . The same force applied to object B causes an acceleration of 3 m/s2. Applied to object C, it causes an acceleration of 8 m/s2. What is the ratio of mass A to mass B?

Bill and his daughter Susan are both standing on identical skateboards (with really good frictionless ball bearings), initially at rest. Bill weighs three times as much as Susan. Bill pushes horizontally on Susan's back, causing Susan to start moving away from Bill. Just after Bill stops pushing,

You are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is

An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point

A truck is using a hook to tow a car whose mass is one quarter that of the truck. If the force exerted by the truck on the car is 6000 N, then the force exerted by the car on the truck is

A person is using a rope to lower a 5.0-N bucket into a well with a constant speed of 2.0 m/s. What is the magnitude of the force exerted by the rope on the bucket?

A fireman is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireman. When the force on his hands equals his weight, what happens to the fireman?

A satellite is in orbit around the earth. Which one feels the greater force?

The acceleration due to gravity is lower on the Moon than on Earth. Which one of the following statements is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true?

You are standing in a moving bus, facing forward, when you suddenly slide forward as the bus comes to an immediate stop. What force caused you to slide forward?

You push on box G that is next to box H, causing both boxes to slide along the floor, as shown in the figure. The reaction force to your push is

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

If you pound a feather with a hammer, which one feels a greater force?

A person who normally weighs 700 N is riding in an elevator that is moving upward but slowing down at a steady rate. If this person is standing on a bathroom scale inside the elevator, what would the scale read?

When two objects slide against one another, which of the following statements about the force of friction between them is true?

When two objects are in contact with no relative motion, which of the following statements about the frictional force between them is true?

When a board with a box on it is slowly tilted to a larger and larger angle, common experience shows that the box will at some point "break loose" and start to accelerate down the board. The box begins to slide once the component of its weight parallel to the board, w||, equals the maximum force of static friction. Which of the following is the most general explanation for why the box accelerates down the board after it begins to slide (rather than sliding with constant speed)?

Which one of the following statements correctly descibes the relationship between the accelerations of blocks A and B?

How does the magnitude of the tension in string 1, T1, compare with the tension in string 2, T2?

In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also massless.

Two boxes P and Q on a perfectly smooth horizontal surface are connected by a light horizontal cord. The mass of P is greater than that of Q. A horizontal force F is applied to box Q as shown in the figure, accelerating the bodies to the right. The magnitude of the force exerted by the connecting cord on body P is

A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The normal force on the box due to the floor is equal to

A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The friction force on the box due to the floor is equal to

As shown in the figure, a woman is straining to lift a large crate, but without success because it is too heavy. We denote the forces on the crate as follows: P is the magnitude of the upward force being exerted on the crate by the person, C is the magnitude of the vertical contact force on the crate by the floor, and W is the weight of the crate. How are the magnitudes of these forces related while the person is trying unsuccessfully to lift the crate?

Two objects have masses m and 5m, respectively. They both are placed side by side on a frictionless inclined ramp and allowed to slide down from rest without any air resistance. Which one of the following statements about these objects is correct?

Two boxes are connected to each other by a string as shown in the figure. The 10-N box slides without friction on the horizontal table surface. The pulley is ideal and the string has negligible mass. What is true about the tension T in the string?

In the figure, a 10-lb weight is suspended from two spring scales, each of which has negligible weight. Which one of the following statements about the readings in the scales is true?

Two objects of unequal masses, M and m (M > m), are connected by a very light cord passing over an ideal pulley of negligible mass. When released, the system accelerates, and friction is negligible.

A block of mass mm sits at rest on a rough inclined ramp that makes an angle θθ with the horizontal. What must be true about force of static friction ff on the block?

Give a specific example of a system with the energy transformation shown.
W→ΔEth

Select a specific example of a system with the energy transformation shown.
U→ΔEth

As the projectile goes upward, what energy changes take place?

At the top point of the flight, what can be said about the projectile's kinetic and potential energy?

The potential energy of the object at the moment of launch __________.

If you hold a heavy weight over your head, the work you do __________.

If you raise an object to a greater height, you are increasing its __________.

If a system is isolated, the total energy of the system ________.

Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct?

Which of the following statements accurately describes the sign of the work done on the box by the force of the push?

Which of the following statements accurately decribes the sign of the work done on the box by the normal force?

Which of the following statements accurately decribes the sign of the work done on the box by the force of kinetic friction?

Which of the following statements accurately decribes the sign of the work done on the box by the force of gravity?

During which interval is the largest amount of energy required to stretch the spring?

A spring is stretched from x=0 to x=d, where x=0 is the equilibrium position of the spring. It is then compressed from x=0 to x=−d. What can be said about the energy required to stretch or compress the spring?

Now consider two springs A and B that are attached to a wall. Spring A has a spring constant that is four times that of the spring constant of spring B. If the same amount of energy is required to stretch both springs, what can be said about the distance each spring is stretched?

Two identical springs are attached to two different masses, MA and MB, where MA is greater than MB. The masses lie on a frictionless surface. Both springs are compressed the same distance, dd, as shown in the figure. Which of the following statements descibes the energy required to compress spring A and spring B? (Figure 2)

Swimmers at a water park have a choice of two frictionless water slides, as shown in the figure. Although both slides drop over the same height h, slide 1 is straight while slide 2 is curved, dropping quickly at first and then leveling out. How does the speed v₁ of a swimmer reaching the bottom of slide 1 compare with v₂, the speed of a swimmer reaching the end of slide 2?

The graphs shown show the magnitude F of the force exerted by a spring as a function of the distance x the spring has been stretched. Which graph would represent the correct relationship between Force applied and distance stretched?

A heavy rock and a light rock are dropped from the same height and experience no significant air resistance as they fall. Which of the following statements about these rocks are correct? (There could be more than one correct choice.)

Two men, Joel and Jerry, push against a car that has stalled, trying unsuccessfully to get it moving. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do on the car.

Which requires more work, increasing a car's speed from 0 mph to 30 mph or from 50 mph to 60 mph?

If the force on an object is in the negative direction, the work it does on the object must be

If the units of your answer are kg • m²/s³, which of the following types of quantities could your answer be?

A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is

When you drop a pebble from height H, it reaches the ground with kinetic energy K if there is no air resistance. From what height should you drop it so it will reach the ground with twice as much kinetic energy?

Jill does twice as much work as Jack does and in half the time. Jill's power output is

When you throw a pebble straight up with initial speed V, it reaches a maximum height H with no air resistance. At what speed should you throw it up vertically so it will go twice as high?

A force produces power P by doing work W in a time T. What power will be produced by a force that does six times as much work in half as much time?

A truck has four times the mass of a car and is moving with twice the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that

A person stands on the edge of a cliff. She throws three identical rocks with the same speed. Rock X is thrown vertically upward, rock Y is thrown horizontally, and rock Z is thrown vertically downward. If the ground at the base of the cliff is level, which rock hits the ground with the greatest speed if there is no air resistance?

A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the wall. Which one of these objects experiences the greater momentum change?

A very light ping-pong ball moving east at a speed of 4 m/s collides with a very heavy stationary bowling ball. The Ping-Pong ball bounces back to the west, and the bowling ball moves very slowly to the east. Which object experiences the greater magnitude impulse during the collision?

The momentum of an isolated system is conserved

A tiger is running in a straight line. If we double both the mass and speed of the tiger, the magnitude of its momentum will increase by what factor?

Consider two less-than-desirable options. In the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. In the second option you are driving 30 mph and crash head-on into a stationary brick wall. In neither case does your car bounce back from the thing it hits, and the collision time is the same in both cases. Which of these two situations would result in the greater impact force on your car?

Two friends are standing on opposite ends of a canoe that is initially at rest with respect to a frictionless lake. The person in the front throws a very massive ball toward the back, and the person in the back catches it. After the ball is caught, the canoe is

In an inelastic collision involving an isolated system, the final total momentum is

In a collision between two unequal masses, which mass receives a greater magnitude impulse?

A 5-kg ball collides inelastically head-on with a 10-kg ball, which is initially stationary. Which of the following statements is true? (There could be more than one correct choice.)

Check all that apply.

Which of the following quantities are units of momentum? (There could be more than one correct choice.)

Check all that apply.