AP Physics Review Dynamics

The diagram above represents the motion of an object that travels to the right in a straight line path. Each dot represents the position of the object at 0.1 s intervals; black dots are labeled with the times at which the object was at that position. Which of the following best estimates the instantaneous speed of the object at time = 1.5 seconds?

• .2 meters/1.5 seconds

• .2 meters/.1 seconds

• 4.5 meters/1.5 seconds

• 4.5 meters/.1 seconds

A person walking along a straight line moves such that her velocity as a function of time can be represented by the graph above. At what time does the person have the same position as she had at time t = 0?

• At t = 5 s

• During the interval 5 s < t < 8 s

• At t = 8 s

• During the interval t > 8 s

A toy car is initially at rest and travels a straight-line distance of 16 meters in T seconds. Starting at time t = 0, the car has a uniform acceleration of 2 m/s² until it reaches a speed of 4 m/s. The car then continues with this velocity time t = T.

What is the value of T?

• 4 s

• 5 s

• 8 s

• 12 s

Tags

NGSS.HS-PS2-1

A student performs an experiment to determine whether an object released from rest truly exhibits free-fall motion. The student takes data of distance d that the object has fallen at various times t after the object is released. If the object does exhibit free-fall motion, which of these graphs will be a line?

• d vs. t

• d vs. t²

• d² vs. t

• d² vs. t²

A car starting from rest accelerates for T seconds with constant acceleration a, traveling a distance D and reaching a speed v. After another T seconds have passed, the car is now a distance 3D from its initial position. What did the car do during the second T-second interval of time?

• The car continued accelerating forward with constant acceleration a.

• The car ceased to accelerate and continued forward with constant velocity v.

• The car slowed down with a backward acceleration –a until it stopped.

• None of these things can account for the car’s final position.

Tags

NGSS.HS-PS2-1

A student conducts an investigation into the motion of a car that accelerates from rest on a straight, level roadway. A driver operating the car causes the car to speed up from rest at time t = 0 and the student makes measurements of the distance traveled and the speed of the car every second.

What experimental evidence would support the conclusion that the car’s acceleration is uniform? Select two answers.

• When starting from rest, the car traveled the same distance as another accelerating car.

• The distance traveled is proportional to the square of the traveling time.

• A graph of velocity vs. time is linear.

• Objects speed up as they accelerate.

Tags

NGSS.HS-PS2-1

James exerts a force on 5N on Julian's hand. What is the force that Julian's hand exerts on James'?

• Greater than 5N
• Less than 5N
• Equal to 5 N
• Julian's does not exert a force on Rushi's

Tags

NGSS.HS-PS2-1

As the angle of the incline increases, what happens to the normal force?

• The normal force increases
• The normal force decreases
• The normal force is not affected by the incline
• The normal force is only dependent on the force due to gravity

Tags

NGSS.HS-PS2-1

The Earth pulls downward on a pingpong ball with a force  of 1N. If this is the "action" force, what is the "reaction" force?

• The ground exerts a force of 1N on the ping pong ball
• The ping pong ball exerts a force of 1 N on the Earth
• The ping pong ball pushes down on the earth with a force of 1N
• The is no reaction force when a gravitational force is involved

Given the FBD, which of the following must be true?

• The frictional force must be accelerating the system to the left.
• The box must be accelerating to the right.
• The box must be moving to the right.
• The FBD is incorrectly drawn. This situation isn't possible

Tags

NGSS.HS-PS2-1