Question

which of the following best describes the difference between speed and acceleration?

a. speed is the distance an object travels within a specific unit of time, whereas acceleration is a measure of the force necessary to change the speed of an object.
b. acceleration is the distance an object travels within a specific unit of time, whereas speed is a measure of the force necessary to change the acceleration of an object.
c. speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
d. acceleration is the distance an object travels within a specific unit of time, whereas speed is the rate at which the acceleration or direction of an object is changing.

Explanation:

Define speed

Speed is a scalar quantity that measures the distance an object travels per unit of time:

$$ \text{Speed} = \frac{\text{Distance}}{\text{Time}} $$

Define acceleration

Acceleration is a vector quantity representing the rate at which an object's velocity (speed and/or direction) changes over time:

$$ \text{Acceleration} = \frac{\Delta \text{Velocity}}{\Delta \text{Time}} $$

Evaluate the given options

• Option A incorrectly defines acceleration as a measure of force.
• Option B swaps the definitions of speed and acceleration, and incorrectly relates speed to force.
• Option C correctly defines speed as distance traveled per unit of time, and acceleration as the rate at which speed or direction changes.
• Option D swaps the definitions of speed and acceleration.

Answer:

• (A) Speed is the distance an object travels within a specific unit of time, whereas acceleration is a measure of the force necessary to change the speed of an object.
• (B) Acceleration is the distance an object travels within a specific unit of time, whereas speed is a measure of the force necessary to change the acceleration of an object.
• (C) Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing. (Correct answer)
• (D) Acceleration is the distance an object travels within a specific unit of time, whereas speed is the rate at which the acceleration or direction of an object is changing.