A block of mass m is initially moving on rough surface inclined at angle θ above the horizontal, as shown in Figure 1. Figure 2 shows the four forces acting on the block. Which of the following best describes the motion of the block at the moment shown in the two figures?

The block is moving down the incline and slowing down.

The block is moving up the incline and speeding up.

The block is moving up the incline and slowing down.

The block is moving down the incline and speeding up.

The block is moving down the incline at a constant speed.

An experiment is set up using a hanging mass to pull a cart along a horizontal track. A light string is attached from the hanging mass over a pulley to a force sensor. A second light string is attached from the force sensor to the cart. There is a motion sensor that can be used to measure different features of the motion of the cart. The pulley is ideal, and there is negligible friction between the cart and the track. (Open link for diagram: https://assets.learnosity.com/organisations/537/VH962571.g02.png) Block A of mass m is at rest on top of block B of mass M when a horizontal force of magnitude F is exerted on block A, for a time Δt as shown in the figure. Block A moves across block B. The coefficient of friction between blocks A and B is μ. There is negligible friction between block B and the surface. Which of the following is a correct expression for the acceleration of block B?

μ m g M \frac{μmg}{M} M μ m g

μ M g m \frac{μMg}{m} m μ M g

μ ( m + M ) g M \frac{μ\left(m+M\right)g}{M} M μ ( m + M ) g

μ M g ( m + M ) \frac{μMg}{\left(m+M\right)} ( m + M ) μ M g

μ ( m + M ) g ( m + M ) \frac{μ\left(m+M\right)g}{\left(m+M\right)} ( m + M ) μ ( m + M ) g

A car is moving along a road over a hill from point A to point B. At point A, the hill has a radius R, and the car has speed v and tangential acceleration a. At point B, the hill has a radius R/2 , and the car has constant speed v/ 2 \sqrt{2} 2 <path d="M95,702c-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5, -10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8, -50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0, 35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5, -221c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467 s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422 s-65,47,-65,47z M834 80H400000v40H845z"> . Which of the following statements about the acceleration of the car at the two points is correct?

The magnitude of the acceleration is greatest at point A because the tangential acceleration at point B is zero.

The magnitude of the acceleration is greatest at point A, and the tangential acceleration at point B is not zero.

The magnitude of the acceleration is greatest at point B.

The magnitude of the acceleration is the same at points A and B.

The magnitude of the accelerations cannot be compared at the two points because they are in different directions.

In an experiment, students set up an inclined plane at an angle θ on a horizontal lab table. The students release a block from rest on the inclined plane, and the block slides down the incline. The students record data for the time it takes the block to reach the bottom of the plane. This procedure is repeated five times, and the data are shown in the table. Which of the following claims could be supported by the experimental results?

Each time the student placed the block on the inclined plane, the incline was pushed downward, decreasing the angle of the incline.

A buildup of dust between the block and the plane during each trial caused a decrease in the coefficient of kinetic friction between the two surfaces.

The student placed the block closer to the bottom of the track during each subsequent trial, decreasing the final velocity.

Contact with the student’s hand during the experiment caused the mass of the block to increase during each trial.

The table that the inclined plane was placed on is tilted slightly upward.

(Diagram is similar as the previous question) Blocks A and B of masses 1.0 kg and 2.5 kg, respectively, are on a horizontal surface and in contact with a circular vertical wall. The vertical wall makes a circle of radius of 1.25 m. Both blocks are also in contact with each other as shown in the top view. The horizontal surface has negligible friction, whereas the coefficient of kinetic friction between the vertical wall and the blocks is 0.20. A force of constant magnitude F is being exerted on block A such that both blocks move around the circular wall. The direction of the force is constantly changing such that it is directed tangent to the circular wall. The figures shown here are top-view force diagrams when the blocks are at the position shown in the original figure. The arrows represent the horizontal forces exerted on the blocks. The frictional force from the wall is represented by f, the normal force from the wall is represented by N, the force the blocks exerted on each other is represented by R, and the horizontal pushing force exerted on block A is represented by F. Which of the following describes evidence from the figures that supports Newton’s third law?

The arrows for the force R are the same size and in opposite directions on the two blocks.

The arrows for f are in the same direction on each block.

The arrow for F on block A is about the size of the addition of the arrows for R and f on block A.

The arrows for N are in the same direction for both blocks.

The arrows for the forces R and f on block B are the same size and in opposite directions.

Block A of mass m A is on a horizontal table of negligible friction. A light string is attached to block A, extends over an ideal pulley, and is attached to block B of mass m B , which is hanging off the table, as shown in the figure. When the blocks are held at rest, the tension in the string is T=m B g . The blocks are then released from rest. Which of the following is a correct expression for the new tension in the string while both blocks are moving?

( m A m B ) ( m A + m B ) g \frac{\left(m_Am_B\right)}{\left(m_A\ +m_B\right)}g ( m A + m B ) ( m A m B ) g

( m A + m B ) g \left(m_A\ +m_B\right)g ( m A + m B ) g

( m A m B ) ( m A − m B ) g \frac{\left(m_Am_B\right)}{\left(m_A\ -\ m_B\right)}g ( m A − m B ) ( m A m B ) g

A cart is released from rest on an inclined plane a distance, D, away from a photogate, as shown in the figure. The cart has a card of length L on top of it. The cart rolls down the incline with negligible friction. As the cart reaches the photogate, the time, Δt, that the card takes to pass through the photogate is measured. Students then divide D by Δt, which yields the average speed of the cart through the photogate. The students then square the average speed and divide by 2D to determine the acceleration of the cart. Which of the following corrections will allow the students to determine the acceleration from the data?

Divide L by Δt to determine the average speed

Divide the average speed by Δt to determine the acceleration.

Divide the square of the average speed by 2L to determine the acceleration.

Divide 2D by Δt 2 to determine the acceleration.

Multiply the length of the placard, L⁢, by two, then divide by the time to go through the photogate, Δt, which will yield the instantaneous speed of the cart through the gate, and then divide by the time to go through the photogate, Δt, to determine the acceleration.

In an experiment, students roll a cart down an inclined plane of negligible friction. The students determined that the cart’s mass is 0.50 kg, and the angle of the inclined plane is 30° above the horizontal. The students use a motion detector to record the acceleration a of the cart as a function of time t. The data are shown in the graph. One student states that the collected data is not valid. Which of the following could be a valid explanation for the flawed data?

The incline is at an angle greater than 30°, increasing the acceleration from what was expected.

There is friction acting on the cart, reducing the acceleration from what was expected.

The cart has a mass greater than 0.5 kg, increasing the acceleration from what was expected.

The surface of the inclined track is not uniform, creating fluctuations in the acceleration as seen with the bumpy line.

The student is incorrect. The data shown are accurate for the information given.

A boy stands in a large bucket used to lift humans to higher elevations. The combined weight of the boy and bucket is W. The bucket has a lightweight rope attached to its top and extending up and over a simple pulley that is attached to the ceiling high above the boy. The rope is long enough to come back down to his hands, as shown. As the boy pulls himself upward, he applies a force F to the rope. Which of the following claims indicates a correct relationship between F and W and provides appropriate reasoning?

F<W, because as the boy exerts a force downward on the rope, the tension in the rope is pulling up on the boy and up on the bucket.

F<W, because as the boy exerts a force downward on the rope, the tension in the rope pulls up on the boy. This is in addition to the normal force the bucket exerts on the boy, thus reducing the force needed to pull the boy upward.

F<W, because as the boy exerts a force downward on the rope, the tension in the rope pulls up on the boy, which reduces his weight.

F=W, because as the boy exerts a force downward on the rope, the tension in the rope pulls up on the boy.

F>W, because as the boy exerts a force downward on the rope, the tension in the rope pulls up on the boy. Plus, the boy must overcome the friction in the pulley.

A rock is suspended from a horizontal support by a string, as shown above. An identical string is attached to the bottom of the rock. A person pulls the bottom string down, starting with a small force and increasing the force slowly until one of the strings breaks. Which of the following correctly indicates which string will break and gives an accurate justification for this claim?

The top string breaks because it has to support the weight of the rock in addition to the force the person exerts on the bottom string.

The top string breaks because the horizontal support exerts more force on the string than the string exerts on the support.

The top string breaks because the person pulls on the bottom string with more force than the horizontal support exerts on the top string.

The bottom string breaks because the person exerts a force on the bottom string, not on the top string.

The bottom string breaks because the inertia of the rock will keep the top string from breaking.

A student of mass M is standing on a scale plate placed on the floor of an elevator. When the elevator is not moving, the reading N on the scale is N = Mg. At some later time, the elevator is moving upward with speed v and slowing down with an acceleration of magnitude a. Based on these data, which of the following statements about N must be correct?

N = m ( g − a ) N=m(g-a) N = m ( g − a )

N = m ( g + v ) N=m(g+v) N = m ( g + v )

N = m ( g − v ) N=m(g-v) N = m ( g − v )

N = m ( g + a ) N=m(g+a) N = m ( g + a )

Data from the motion detector is used to produce the graph shown for the speed as a function of time for the filter as it falls to the ground. Which of the following describes the speed and magnitude of acceleration of the coffee filter as it falls?

Speed: Increasing Magnitude of the Acceleration: Decreasing

Speed: Increasing Magnitude of the Acceleration: Increasing

Speed: Decreasing Magnitude of the Acceleration: Decreasing

Speed: Decreasing Magnitude of the Acceleration: Increasing

Speed: Increasing Magnitude of the Acceleration: Remains the same

MCQ Unit 2: Newton's Laws of Motion Quiz

1.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A 1600kg car is traveling over a hill that has a radius of curvature of 25m. The car is slowing down as it goes over the hill. It slows down at a constant rate from a speed of 25 m/s to a speed of 10 m/s over a distance of 50 m ending at the top of the hill. The net acceleration of the car at the top of the hill is most nearly

4.0 $\frac{m}{s^2}$

5.3 $\frac{m}{s^2}$

6.6 $\frac{m}{s^2}$

9.3 $\frac{m}{s^2}$

26 $\frac{m}{s^2}$

Tags

NGSS.HS-PS2-1

2.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

Blocks A and B have masses M and 2M, respectively. The blocks are connected using a light string and an ideal pulley in the Atwood machine shown. When the blocks are released from rest, block B accelerates downward with acceleration a. Block B is replaced with a block that has twice the mass. The blocks are again released from rest. Which of the following is a correct expression for the new acceleration of the blocks?

$\frac{1}{3}a$

$\frac{5}{9}a$

$\frac{3}{5\ }a$

$\frac{9}{5}a$

$2a$

Tags

NGSS.HS-PS2-1

3.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A block of mass m is sliding down an inclined plane that makes an angle θ with the horizontal, as shown in the figure. The coefficient of kinetic friction between the surface and the block is μ . Which of the following is a correct expression for the acceleration a of the block?

$g(1-μ\cosθ)$

$g(\sinθ−μ\cosθ)$

$g(1+μ\cosθ)$

$g(\sinθ+μ\cosθ)$

$g(\sinθ−\cosθ)$

Tags

NGSS.HS-PS2-1

4.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

Blocks A and B of equal mass are on a horizontal surface and are connected by a light string. The blocks are pulled to the right by a horizontal force of magnitude F exerted on block B, as shown in the figure. There is negligible friction between the blocks and the horizontal surface. The blocks are accelerating to the right along the surface. Which of the following figures accurately represents the magnitudes and directions of the horizontal forces on the blocks?

Tags

NGSS.HS-PS2-1

5.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A 650 kg car moving to the right at 20 m/s collides with a stationary 2250 kg truck. Which of the following graphs could represent the force as a function of time for both the car and the truck during the collision?

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

6.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A cart of mass M is approaching a hill with a circular top of radius R, as shown in the figure above. The cart is carrying a load also of mass M and is traveling with speed v₀ when it is at the top of the hill. The length of the cart is negligible in comparison to the radius of the hill. The cart never loses contact with the hill’s surface. The cart and load can both be considered to be at the same position.

Which of the following claims identifies an action-reaction pair of forces due to Newton’s third law and provides appropriate reasoning to justify this claim?

The normal force exerted on the load by the cart and the gravitational force exerted on the load by Earth, because these are equal and opposite forces that act on the same object.

The normal force exerted on the load by the cart and the gravitational force exerted on the load by Earth, because these are equal and opposite forces that act on different objects.

The normal force exerted on the load by the cart and the normal force exerted on the cart by the load, because these are equal and opposite forces that act on the same object.

The normal force exerted on the load by the cart and the normal force exerted on the cart by the load, because these are equal and opposite forces that act on different objects.

The gravitational force exerted on the cart by Earth and the normal force exerted by the hill on the cart, because these are equal and opposite forces that act on different objects.

7.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A cart of mass M is approaching a hill with a circular top of radius R, as shown in the figure above. The cart is carrying a load also of mass M and is traveling with speed v₀ when it is at the top of the hill. The length of the cart is negligible in comparison to the radius of the hill. The cart never loses contact with the hill’s surface. The cart and load can both be considered to be at the same position.

The speed v_min is the minimum speed necessary for the cart and the load to leave the surface of the hill at the top of the hill. If the load is removed, what is the new minimum speed necessary for the cart to leave the surface of the hill?

$\frac{1}{4}\ v_{\min}$

$\frac{1}{2}\ v_{\min}$

$v_{\min}$

$2\ v_{\min}$

$4\ v_{\min}$

Tags

NGSS.HS-PS2-1

8.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

A cart of mass M is approaching a hill with a circular top of radius R, as shown in the figure above. The cart is carrying a load also of mass M and is traveling with speed v₀ when it is at the top of the hill. The length of the cart is negligible in comparison to the radius of the hill. The cart never loses contact with the hill’s surface. The cart and load can both be considered to be at the same position.

In a free-body diagram showing all the forces (and not components) acting on objects at the top of the hill, how many vertical forces will act on the cart, and how many vertical forces will act on the load?

Cart: 2; Load: 2

Cart: 2; Load: 3

Cart: 3; Load: 2

Cart: 3; Load: 3

Cart: 4; Load: 3

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

9.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

An Atwood's machine consists of two blocks connected by a light string that passes over a set of ideal pulleys, as shown above. Blocks A and B have masses 1/2 M and M , respectively. The blocks are released from rest and block B moves downward with an acceleration of magnitude a. Next, a block of mass 1/4 M is attached to block A , and the system is again released from rest. Which of the following gives the change in acceleration of block B ?

A decrease of $\frac{1}{3\ }g$

A decrease of $\frac{1}{7\ }g$

An increase of $\frac{1}{7\ }g$

A decrease of $\frac{4}{21\ }g$

An increase of $\frac{4}{21\ }g$

Tags

NGSS.HS-PS2-1

10.

MULTIPLE CHOICE QUESTION

2 mins • 1 pt

Blocks A and B of masses m_A and m_B, respectively, are attached to an ideal pulley to create the Atwood’s machine shown in the figure. Which of the following free-body diagrams could be correct for the blocks when they are released from rest if m_B>m_A?

Tags

NGSS.HS-PS2-1

MCQ Unit 2: Newton's Laws of Motion

37 questions

A block of mass m is sliding down an inclined plane that makes an angle θ with the horizontal, as shown in the figure. The coefficient of kinetic friction between the surface and the block is μ . Which of the following is a correct expression for the acceleration a of the block?

A 650 kg car moving to the right at 20 m/s collides with a stationary 2250 kg truck. Which of the following graphs could represent the force as a function of time for both the car and the truck during the collision?

Blocks A and B of masses m_A and m_B, respectively, are attached to an ideal pulley to create the Atwood’s machine shown in the figure. Which of the following free-body diagrams could be correct for the blocks when they are released from rest if m_B>m_A?

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MCQ Unit 2: Newton's Laws of Motion

37 questions

A block of mass m is sliding down an inclined plane that makes an angle θ with the horizontal, as shown in the figure. The coefficient of kinetic friction between the surface and the block is μ . Which of the following is a correct expression for the acceleration a of the block?

A 650 kg car moving to the right at 20 m/s collides with a stationary 2250 kg truck. Which of the following graphs could represent the force as a function of time for both the car and the truck during the collision?

Blocks A and B of masses mA and mB, respectively, are attached to an ideal pulley to create the Atwood’s machine shown in the figure. Which of the following free-body diagrams could be correct for the blocks when they are released from rest if mB>mA?

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Blocks A and B of masses m_A and m_B, respectively, are attached to an ideal pulley to create the Atwood’s machine shown in the figure. Which of the following free-body diagrams could be correct for the blocks when they are released from rest if m_B>m_A?