Question

If a runner decreases their velocity from 20 m/s to 10 m/s in 2.0 seconds, what is their average acceleration?

A. 5 m/s^2
B. -5 m/s^2
C. 2.5 m/s^2
D. -2.5 m/s^2

Answer 1

The average acceleration of the runner is -5 m/s^2.

Step-by-step explanation:

To find the average acceleration, we can use the formula:

average acceleration = (final velocity - initial velocity) / time

Given that the initial velocity is 20 m/s, the final velocity is 10 m/s, and the time is 2.0 seconds, we can substitute these values into the formula:

average acceleration = (10 m/s - 20 m/s) / 2.0 s = -5 m/s^2

Therefore, the correct answer is B. -5 m/s^2.