Question

A quantity has a value of $-16\mathrm{m}/{\mathrm{s}}^2$. What does this quantity indicate?

Answer 1

Acceleration and Deceleration

1. Acceleration is the positive rate of change of velocity of an object. When an object is accelerating, it means that its velocity is increasing with time. Its units is ${\mathrm{ms}}^{-2}$or $\mathrm{m}/{\mathrm{s}}^2$.
2. Deceleration is the opposite of acceleration. Its unit is the same as that of acceleration. When an object is decelerating, it means that its velocity is decreasing over time. Thus, deceleration is just negative acceleration.

Therefore, the given quantity indicates deceleration.