---
title: "AP Physics 1 Unit 3 Practice Test"
description: "A timed AP Physics 1 Unit 3 (Work, Energy, and Power) practice test in the AP format, drawn from 1,073 multiple-choice questions and 41 FRQs written for the unit. The standard version takes about 88 minutes."
canonical: "https://fiveable.me/ap-physics-1-revised/unit-test/3"
type: "unit-test"
subject: "AP Physics 1"
unit: "Unit 3"
---

# AP Physics 1 Unit 3 Practice Test

## Overview

A timed AP Physics 1 Unit 3 (Work, Energy, and Power) practice test in the AP format, drawn from 1,073 multiple-choice questions and 41 FRQs written for the unit. The standard version takes about 88 minutes.

## Test Format

- 20 Multiple Choice Questions (40 minutes)
- 1 FRQ – FRQ 1 – Mathematical Routines (24 minutes)
- 1 FRQ – FRQ 2 – Translation Between Representations (24 minutes)

## Unit FRQs by Type

- [FRQ 1 – Mathematical Routines](/ap-physics-1-revised/frqs/mathematical-routines?unit=3): 11 questions
- [FRQ 2 – Translation Between Representations](/ap-physics-1-revised/frqs/translation-between-representations?unit=3): 10 questions
- [FRQ 3 – Experimental Design](/ap-physics-1-revised/frqs/experimental-design?unit=3): 6 questions
- [FRQ 4 – Qualitative/Quantitative Translation](/ap-physics-1-revised/frqs/qualitative-quantitative-translation?unit=3): 14 questions

## Practice Questions

### Question 1

An object of mass $$m$$ moves with speed $$v$$ and translational kinetic energy $$K$$. If the object accelerates to a speed of $$3v$$ while its mass remains constant, which expression represents its new translational kinetic energy?

- (A) $$3K$$
- (B) $$6K$$
- (C) $$9K$$
- (D) $$27K$$

**Answer: (C)** Translational kinetic energy depends on the square of the velocity ($$K \propto v^2$$). Tripling the speed results in a factor of $$3^2 = 9$$ change in kinetic energy.

### Question 2

A block of mass $$m$$ travels at speed $$v$$ with kinetic energy $$K_0$$. A second block has mass $$0.5m$$ and travels at speed $$2v$$. What is the kinetic energy of the second block in terms of $$K_0$$?

- (A) $$0.5 K_0$$
- (B) $$1.0 K_0$$
- (C) $$2.0 K_0$$
- (D) $$4.0 K_0$$

**Answer: (C)** Kinetic energy is proportional to $$m$$ and $$v^2$$. The new energy is proportional to $$(0.5)(2^2) = (0.5)(4) = 2$$, resulting in $$2.0 K_0$$.

### Question 3

A vehicle traveling at speed $$v$$ requires a braking distance $$d$$ to stop. Assuming the braking force is constant, what braking distance is required if the vehicle is traveling at speed $$2v$$?

- (A) $$d$$
- (B) $$\sqrt{2}d$$
- (C) $$2d$$
- (D) $$4d$$

**Answer: (D)** Stopping distance is proportional to kinetic energy ($$W = Fd = \Delta K$$). Since $$K \propto v^2$$, doubling speed quadruples kinetic energy, requiring four times the distance to stop.

### Question 4

A stone dropped from height $$h$$ reaches the ground with kinetic energy $$K$$. If the stone is instead dropped from height $$2h$$ and air resistance is negligible, what is its kinetic energy upon reaching the ground?

- (A) $$\sqrt{2}K$$
- (B) $$2K$$
- (C) $$4K$$
- (D) $$8K$$

**Answer: (B)** Gravitational potential energy ($$U_g = mgh$$) converts directly to kinetic energy. Since $$U_g \propto h$$, doubling the height doubles the final kinetic energy.

### Question 5

An observer standing on the ground measures the kinetic energy of a car moving at velocity $$v$$ as $$K$$. A second observer is moving in the same direction as the car at velocity $$v/2$$. What value does the second observer measure for the car's kinetic energy?

- (A) $$K/4$$
- (B) $$K/2$$
- (C) $$K$$
- (D) $$2K$$

**Answer: (A)** The relative velocity of the car to the observer is $$v - v/2 = v/2$$. Since $$K \propto v^2$$, the measured energy is proportional to $$(1/2)^2 = 1/4$$ of the original value.

### Question 6

A satellite of mass $$m$$ orbits a planet in a circular path of radius $$R$$ with kinetic energy $$K$$. If the satellite is moved to a circular orbit of radius $$2R$$, what is the new kinetic energy? (Note: For a circular orbit, $$v = \sqrt{GM/R}$$).

- (A) $$K/4$$
- (B) $$K/2$$
- (C) $$K$$
- (D) $$2K$$

**Answer: (B)** Orbital velocity squared is inversely proportional to radius ($$v^2 \propto 1/R$$). Since $$K \propto v^2$$, doubling the radius halves the kinetic energy.

### Question 7

A cart moves along a track with kinetic energy $$K$$. As it passes under a hopper, sand is dropped into the cart, tripling its total mass while its speed remains constant. What is the new kinetic energy of the cart?

- (A) $$K/3$$
- (B) $$K$$
- (C) $$3K$$
- (D) $$9K$$

**Answer: (C)** Translational kinetic energy is directly proportional to mass ($$K \propto m$$). Tripling the mass while keeping speed constant triples the kinetic energy.

### Question 8

Object A has mass $$m$$ and speed $$v$$. Object B has mass $$4m$$. If both objects have the same translational kinetic energy, what is the speed of Object B?

- (A) $$v/4$$
- (B) $$v/2$$
- (C) $$2v$$
- (D) $$4v$$

**Answer: (B)** For kinetic energies to be equal ($$\frac{1}{2}mv^2 = \frac{1}{2}(4m)v_B^2$$), $$v^2 = 4v_B^2$$. Taking the square root gives $$v_B = v/2$$.

### Question 9

An object has momentum $$p$$ and kinetic energy $$K$$. If the object's momentum is doubled while its mass remains constant, what is the new kinetic energy?

- (A) $$K/2$$
- (B) $$2K$$
- (C) $$4K$$
- (D) $$8K$$

**Answer: (C)** Kinetic energy is related to momentum by $$K = p^2/2m$$. Doubling momentum ($$p \to 2p$$) results in a factor of $$2^2 = 4$$ increase in kinetic energy.

### Question 10

A block launched by a spring compressed by distance $$x$$ has exit kinetic energy $$K$$. If the spring is compressed by distance $$3x$$, what is the exit kinetic energy?

- (A) $$3K$$
- (B) $$6K$$
- (C) $$9K$$
- (D) $$27K$$

**Answer: (C)** Elastic potential energy ($$U_s = \frac{1}{2}kx^2$$) converts to kinetic energy. Since $$U_s \propto x^2$$, tripling the compression increases the energy by a factor of $$3^2 = 9$$.

## Review the Unit

- [3.1 Translational Kinetic Energy](/ap-physics-1-revised/unit-3/1-translational-kinetic-energy/study-guide/jiKKHhAZFwLOFh5N)
- [3.2 Work](/ap-physics-1-revised/unit-3/2-work/study-guide/wIYF5CugCCQZCGKx)
- [3.3 Potential Energy](/ap-physics-1-revised/unit-3/3-potential-energy/study-guide/JOHf0KeXoaldDqpO)
- [3.4 Conservation of Energy](/ap-physics-1-revised/unit-3/4-conservation-of-energy/study-guide/ryRjnKmvIfMWNvdl)
- [3.5 Power](/ap-physics-1-revised/unit-3/5-power/study-guide/S31ApPYjGfgL2Twn)

## Other Unit Tests

- [Unit 1: Kinematics](/ap-physics-1-revised/unit-test/1)
- [Unit 2: Force and Translational Dynamics](/ap-physics-1-revised/unit-test/2)
- [Unit 4: Linear Momentum](/ap-physics-1-revised/unit-test/4)
- [Unit 5: Torque and Rotational Dynamics](/ap-physics-1-revised/unit-test/5)
- [Unit 6: Rotating Systems: Energy & Momentum](/ap-physics-1-revised/unit-test/6)
- [Unit 7: Oscillations](/ap-physics-1-revised/unit-test/7)
- [Unit 8: Fluids](/ap-physics-1-revised/unit-test/8)

## About This Document

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- [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns
- [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing
- [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`)
- [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`)