Question

A gazelle is running in a straight line with a constant velocity of 1340 m/min. A cheetah can accelerate from 0 m/min to 1820 m/min in 3 seconds. What is the average acceleration of the gazelle? What is the average acceleration of the cheetah?

Answer 1

The gazelle has zero average acceleration because it's moving at a constant speed. Constant speed means no change in speed means zero acceleration.

The cheetah, on the other hand, changes its speed from 0 m/min to 1820 m/min in a matter of 3 seconds, so its average acceleration is

a[ave] = (1820 m/min - 0 m/min) / (3 s)

… = (1820 m/min) / (3/60 min)

… = 36,400 m/min²

… = (36,400 m) / (60 s)²

… = 91/9 m/s² ≈ 10.1 m/s²