AP Physics 1: Algebra-Based Unit 3: Work, Energy, and Power Practice Exam

1. [Skill: 2.A | Topic: 3.3] A student moves a 2.0 kg object vertically from Position 1 to Position 2 near Earth’s surface. The student’s data are shown. [Image Cue]: Data table, "Vertical Position Data", columns: Position (1, 2) and Height y (m). Values: Position 1: y = 0.20 m; Position 2: y = 1.70 m. Note: g = 9.8 m/s^2. Which of the following is the best estimate of the change in gravitational potential energy of the Earth-object system, from Position 1 to Position 2?

2. [Skill: 2.A | Topic: 3.3] An ideal spring with spring constant $k = 200\ \text{N/m}$ is on a horizontal frictionless table. A block is pushed against the spring so that the spring’s length changes by $\Delta x$ from its equilibrium length. Which of the following gives the elastic potential energy stored in the spring when it is compressed by $0.10\ \text{m}$?

3. [Skill: 6.B | Topic: 3.3] A book rests on a shelf. A student claims, “The book has gravitational potential energy because it is high above the floor.” Which statement best corrects the student’s claim, using the concept of potential energy as described in AP Physics 1?

4. [Skill: 1.B | Topic: 3.3] A student analyzes the gravitational potential energy of an Earth-ball system for a ball that moves between two points. Point A is at height 0.50 m above the floor, and Point B is at height 2.00 m above the floor. The student first defines the zero of gravitational potential energy to be at the floor. A lab partner instead defines the zero of gravitational potential energy to be at Point A. Which statement is correct about how this change affects the gravitational potential energy values and the change in gravitational potential energy from A to B?

5. [Skill: 1.A | Topic: 3.4] A student analyzes the motion of a hockey puck that has been struck and is sliding across nearly frictionless ice. The student defines the system to be the puck only (the Earth and the stick are not included in the system). Which of the following best describes the energies that can be associated with this system during the puck’s motion?

6. [Skill: 2.B | Topic: 3.4] A cart of mass 0.50 kg moves on a frictionless track. At point P (higher on the track), the cart has speed 3.0 m/s and is 2.0 m above point Q (the bottom). Assume $g = 9.8\ \text{m/s}^2$. If the system is the cart + Earth and the cart moves from P to Q, what is the cart’s speed at point Q?

7. [Skill: 6.A | Topic: 3.4] A block is pushed across a rough, horizontal surface and eventually comes to rest due to kinetic friction. Consider the following two possible system choices: System 1: the block only System 2: the block + surface + Earth Which statement best compares energy accounting for the two systems during the slide?

8. [Skill: 2.B | Topic: 3.5] Two students use different winches to lift the same 50 kg crate vertically upward a distance of 5.0 m at a steady speed. Winch A raises the crate in 2.0 s. Winch B raises the crate in 5.0 s. Assume the only significant energy transfer is from the winch to the gravitational potential energy of the crate-Earth system (use $g=9.8\ \text{m/s}^2$). What is the ratio of the average power delivered by Winch A to that delivered by Winch B?

9. [Skill: 2.A | Topic: 3.5] A student pulls a sled across level snow using a rope that exerts a constant force of magnitude 40 N at an angle of $30^\circ$ above the horizontal. At a particular instant, the sled’s speed is 3.0 m/s and its velocity is horizontal. What is the instantaneous power delivered to the sled by the pulling force at that instant?

10. [Skill: 1.B | Topic: 3.5] A system’s total energy $E$ is measured as a function of time $t$ and shown in the graph. [Image Cue]: Graph, "Energy of a System vs. Time", horizontal axis labeled $t$ (s) from 0 to 6, vertical axis labeled $E$ (J). The graph is a straight line increasing from (0 s, 200 J) to (4 s, 800 J), then a horizontal line from (4 s, 800 J) to (6 s, 800 J). Which statement best describes the power associated with energy transfer into the system during the time intervals shown?

11. [Skill: 2.B | Topic: 3.2] A block of mass $m$ is pulled a distance $d$ along a horizontal surface by a constant force of magnitude $F$ directed at an angle $\theta$ above the horizontal. The coefficient of kinetic friction between the block and the surface is $\mu_k$. Which of the following expressions represents the net work done on the block during the displacement $d$?

12. [Skill: 2.2 | Topic: 3.1] A student conducts an experiment to analyze the translational kinetic energy of different laboratory carts. In the first trial, a cart of mass $m$ moves with a constant speed $v$ and is measured to have a translational kinetic energy $K$. In the second trial, a cart with mass $m/2$ moves with a constant speed $2v$. Which of the following represents the translational kinetic energy of the cart in the second trial? (A) $K/2$ (B) $K$ (C) $2K$ (D) $4K$