Question

the runners in the picture below have just started a race. they started at rest and are getting faster.

what statement best describes the motion of the runners at the beginning of the race?

a. velocity remains the same and speed is positive.
b. velocity and speed both remain constant.
c. acceleration is positive and speed is increasing.
d. acceleration and speed both remain constant.

Explanation:

Analyze the initial state of motion

Using the Kinematics Definitions knowledge point

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Determine the change in speed and acceleration

Using the Speed vs Acceleration knowledge point

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Evaluate the given options

Using the Speed vs Acceleration and Kinematics Definitions knowledge points

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$$

Answer:

• A. Velocity remains the same and speed is positive.
• B. Velocity and speed both remain constant.
• C. Acceleration is positive and speed is increasing. (Correct answer)
• D. Acceleration and speed both remain constant.