Question

A stone falls from rest with a constant acceleration of 9.81 m/s2. How fast is it moving after 5 seconds?

Answer 1

By definition, a constatn acceleration relates to the speed in the following manner:

$$g = \dfrac{v}{t}$$

extracting $v$, obtain:

$$v = gt$$

Substituting numerical values: $g = 9.81m/s^2$ and $t = 5s$, get:

$$v = 9.81\cdot 5 = 49.05 m/s$$

Answer. 49.05 m/s.