Part 1 Semester Review (Motion 101)

Multiple Choice

The graph describes the motion of a car that was initially heading north along a straight north-south road. Each of the five labeled intervals on the graph – A,B,C,D and E – lasts for the same amount of time. North is the positive direction. Over which interval(s) is the velocity of the object greater than zero?

• interval A, only

• interval B, only

• interval D, only

• intervals A, B, and C

• intervals A, B, C, and D

Multiple Choice

The graph describes the motion of a car that was initially heading north along a straight north-south road. Each of the five labeled intervals on the graph – A,B,C,D and E – lasts for the same amount of time. North is the positive direction. Over which interval does the object have the greatest average speed?

• interval A,

• interval B

• interval C

• intervals D

• intervals E

Multiple Choice

At what time after 0 seconds will the object first return to its starting point?

• 3 sec

• 6 sec

• 9 sec

• 12 sec

• Sometime after 12 sec

Multiple Choice

At what time shown on the graph does the object first begin to reduce its speed?

• 0 sec

• 3 sec

• 6 sec

• 9 sec

• 12 sec

Multiple Choice

At what time after 0 seconds does the object first begin to travel southward?

• 0 sec

• 3 sec

• 6 sec

• 9 sec

• 12 sec

Multiple Choice

A box slides horizontally to the right. The graph shows the box's velocity as a function of time. Which of the following statements correctly describes the motion of the box?

• The box is moving at a constant velocity from t=0 seconds to t=8 seconds.

• The box ends up back at its starting point between t=5 seconds and t=6 seconds.

• The box begins decreasing its speed between t=5 seconds and t=6 seconds.

• The box begins changes directions between t=5 seconds and t=6 seconds.

Multiple Choice

The graph above shows the velocity versus time for an object moving in a straight line. At what time after t = 0 does the object again pass through its initial position at zero seconds?

• Between 0 and 1 s

• 1 s

• Between 1 and 2 s

• 2 s

• Between 2 and 3 s

Multiple Choice

Which pair of graphs below shows the distance traveled versus time and the speed versus time for an object uniformly accelerated from rest starting at time t = 0?

Multiple Choice

A small cart is rolling freely on a ramp with a constant acceleration of 0.5 m/s² west. Initially, the cart has a velocity of 2.0 m/s East. If the cart never leaves the ramp, which of the following best describes the motion of the cart after 5 seconds?

• The cart is traveling East and it is slowing down.

• The cart is traveling East and is speeding up.

• The cart is traveling West and is slowing down.

• The cart is traveling West and is speeding up.

Multiple Choice

A car is moving at a constant velocity of 20 m/s when the driver hits the brakes because she sees an animal run across the street in front of the car. If the car experiences an acceleration of -2.5 m/s² and the driver brakes for 2 seconds before taking her foot off the brake pedal, how fast will the car be moving after braking?

• 15 m/s

• 17.5 m/s

• 22.5 m/s

• 25 m/s

Multiple Choice

A coin is dropped from the top of a tall building. Assuming air resistance is negligible, how fast would the coin be moving after 6 seconds of falling?

• 0 m/s

• 30 m/s

• 60 m/s

• 120 m/s

Multiple Choice

Identical spheres are released from a device at time t = 0 from the same height H, as shown above. Sphere A has no initial velocity and falls straight down. Sphere B is given an initial horizontal velocity of magnitude v₀ and travels a horizontal distance D before it reaches the ground. The spheres reach the ground at the same time t_f, even though sphere B has more distance to cover before landing. Air resistance is negligible. Which statement below best explains why both spheres hit the ground at the same time?

• Since air resistance is negligible, the only force acting on the spheres is gravity, which means the spheres will fall with a constant rate of acceleration.

• Sphere A and Sphere B are released at the same time from the same height, thus they will hit at the same time.

• The horizontal component of velocity has no effect on the vertical component of velocity.

• All the statements above are correct.

Multiple Choice

A ball is thrown off an 8 m cliff with a horizontal speed of 5 m/s and falls a distance of d away from the cliff and takes a time of t to fall. If the initial horizontal speed is doubled, what would happen to the distance the ball traveled from the cliff?

• d

• d/2

• 2d

• 4d

Multiple Choice

A ball is thrown off an 8 m cliff with a horizontal speed of 5 m/s and falls a distance of d away from the cliff and takes a time of t to fall. If the initial horizontal speed is doubled, what would happen to the time the ball takes to fall from the cliff?

• t

• t/2

• 2t

• 4t

Multiple Choice

A projectile is launched over level ground so that its initial velocity has components (v_x = 20 m/s, v_y = 30 m/s). Ignore the effects of air resistance. How much time elapses before the projectile strikes the ground? (Note use g = 10 m/s²)

• 2 sec

• 3 sec

• 4 sec

• 6 sec

Multiple Choice

A projectile is launched over level ground so that its initial velocity has components (v_x = 20 m/s, v_y = 30 m/s). Ignore the effects of air resistance. What is the projectile's speed at the instant it reaches its maximum height above the ground?

• 0 m/s

• 30 m/s

• 20 m/s

• 50 m/s