Stemscopes Exam STEMscopes Forces and Motion 2 — Questions and Answers
Question 1: Which of the following correctly describes velocity?
- Speed only, without direction
- Distance traveled divided by time
- Speed with a specified direction (Correct answer)
- The rate of change of acceleration
Correct answer: Speed with a specified direction
Velocity is a vector quantity that includes both speed (magnitude) and direction of motion.
Question 2: A distance-time graph shows a straight horizontal line. What does this indicate about the object's motion?
- The object is accelerating
- The object is moving at constant speed
- The object is stationary (Correct answer)
- The object is decelerating
Correct answer: The object is stationary
A horizontal line on a distance-time graph means distance is not changing with time, indicating the object is stationary.
Question 3: A skateboarder rolls down a ramp and gains speed. Which energy transformation is occurring?
- Kinetic energy to potential energy
- Potential energy to kinetic energy (Correct answer)
- Chemical energy to kinetic energy
- Thermal energy to kinetic energy
Correct answer: Potential energy to kinetic energy
As the skateboarder descends the ramp, gravitational potential energy is converted into kinetic energy, causing increased speed.
Question 4: Which factor does NOT directly affect the gravitational force between two objects?
- Mass of object 1
- Mass of object 2
- Distance between the objects
- Color of the objects (Correct answer)
Correct answer: Color of the objects
Gravitational force depends on the masses of both objects and the distance between them; color has no effect on gravity.
Question 5: A ball is thrown straight up into the air. At the highest point, the ball's velocity is:
- At its maximum
- Equal to its initial velocity
- Zero (Correct answer)
- Negative and increasing
Correct answer: Zero
At the highest point of its trajectory, the ball momentarily stops moving upward before falling back down, so its velocity is zero.
Question 6: What does the slope of a velocity-time graph represent?
- Distance
- Speed
- Acceleration (Correct answer)
- Force
Correct answer: Acceleration
The slope of a velocity-time graph equals the change in velocity divided by change in time, which is the definition of acceleration.
Question 7: A 5 kg object and a 10 kg object are dropped from the same height in a vacuum. Which hits the ground first?
- The 5 kg object, because it is lighter
- The 10 kg object, because it is heavier
- They hit at the same time (Correct answer)
- It depends on their shapes
Correct answer: They hit at the same time
In a vacuum, all objects fall with the same gravitational acceleration (9.8 m/s²) regardless of mass, so they hit the ground simultaneously.
Stemscopes Exam STEMscopes Forces and Motion 2
Which of the following correctly describes velocity?