Displacement, Velocity & Acceleration (College Board AP® Physics 1: Algebra-Based): Exam Questions

Figure 1

A long track, inclined at an angle to the horizontal, has small speed bumps on it. The bumps are evenly spaced a distance apart, as shown in Figure 1. The track is actually much longer than shown, with over 100 bumps. A cart of mass is released from rest at the top of the track. A student notices that after reaching the 40th bump, the cart's average speed between successive bumps no longer increases, reaching a maximum value . This means the time taken to move from one bump to the next becomes constant.

Consider the cart's motion between bump 41 and bump 44.

i) On the axes provided in Figure 2, sketch a graph of the cart's velocity as a function of time from the moment it reaches bump 41 until it reaches bump 44.

ii) On your graph, draw and label a line for the maximum average speed for the same time interval.

Figure 2

Derive an expression for the time taken for the cart to travel between two successive bumps. Write your expression in terms of , , , and physical constants as appropriate. Begin your derivation by writing a fundamental physics principle or an equation from the reference booklet.

One end of an elastic climbing rope is fixed to the top of a crane. The other end of the rope is connected to a block which is initially at position A. The block is released from rest. The mass of the rope is negligible. 

The full length of the rope is 60.0 m. From position A to B, the block falls freely. 

Identify whether the acceleration of the block is less than, equal to, or greater than .

⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ ‎ ‎ ‎‎ ‎ ‎ ‎ ‎ ‎ ‎ ⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽

Justify your reasoning.

Between position B and C the resultant force on the block changes, because the tension in the rope increases as the rope extends. 

Student A makes the following claim:

"A kinematic equation can be used to find the vertical velocity of the lock at position B."

Identify whether Student A is correct or incorrect.

⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ correct ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ incorrect

Justify your answer.

Figure 1

Figure 1 shows the flight path of a drone conducting a LiDAR (Light Detection and Ranging) scan of a ranch in Utah. The drone flies a grid pattern consisting of 500 m horizontal paths which shift to the north by 50 m with each pass.

Estimate the distance covered by drone during its flight.

Determine the displacement of the LiDAR drone. Justify your answer.