Gravity + Kinetic Energy

A group of students were experimenting with how size, mass, and shape affect how fast objects fall. Two pieces of paper that are the same size and mass are dropped at the same time from the top of the ladder. One is flat and the other crumpled into a ball. Which piece of paper will hit the ground first? Choose the one best answer

• ❍ A The crumpled ball of paper will hit the ground first.
• ❍ B The smooth, flat piece of paper will hit the ground first.
• ❍ C Both pieces of paper will hit the ground at the same time.
• ❍ D More information is needed to determine which ball will hit the ground first.

Two balls that look exactly the same but have different masses are dropped at the same time from the top of the ladder. Which ball will hit the ground first? (Choose the one best answer)

• ❍ F The ball with more mass will hit the ground first.
• ❍ G The ball with less mass will hit the ground first.
• ❍ H Both balls will hit the ground at the same time.
• ❍ J More information is needed to determine which ball has more kinetic energy

Which equation would you use to find the acceleration of an automobile whose speed decreases from 48 m/s to 4 m/s in 11 seconds? (Choose the one best answer.)

• ❍ A (48 m/s – 4 m/s) / 11 s = 4 m/s2
• ❍ B (48 m/s + 4 m/s ) / 11 s = 4.7 m/s2
• ❍ C (4 m/s – 48 m/s) = - 44 m/s
• ❍ D (4 m/s – 48 m/s) / 11 s = - 4 m/s2

A group of students are walking at a speed of 2 m/s. Which row of data indicates their position at each second? (Mark the one best answer.)

• A
• B
• C
• D

If a car travels a distance of 100 kilometers (km) in 2 hours, what is its average speed? (Choose the one best answer.)

• A 50 km per hour
• B 200 km per hour
• C 0.2 km per hour
• D More information is needed to know the average speed.

A ball rolls slowly to the edge of a building’s roof. Which of the following best describes the ball’s motion after it passes the edge of the roof? (Choose the one best answer.)

• A The ball falls at a constant speed of about 1 meter per second per second.
• B The ball falls at a constant speed of about 10 meters per second.
• C The ball falls with a speed that increases by about 1 meter per second.
• D The ball falls with a speed that increases by about 10 meters per second per second.

An object is moving at a constant speed. Every second, the object’s speed is measured. At 2 seconds (s), a single constant force begins to slow the object down. This force continues to act upon the object during the remaining time shown in the table. Which row of the following table could be a correct representation of the object’s speed after each second? (Choose the one best answer.)

• A
• B
• C
• D

Acceleration is ______________________. (Choose the one best answer.)

• A going faster and faster
• B going slower and slower
• C change in speed over time
• D going really fast

A race car accelerated from rest to 60 m/s when it crossed the finish line 8 seconds later. What was the car’s acceleration?

• A. 0.13 m/s2
• B. 7.5 m/s2
• C. 52 m/s2
• D. 68 m/s2

A meteor changed speed from 1.8 km/s to 1 km/s in 0.03 seconds. What was the acceleration of the meteor?

• A. 26.7 km/s2
• B. -26.7 km/s2
• C. -33.3 km/s2
• D. 60 km/s