Question

A body thrown vertically down from a height moves 40m during the 4th second of its motion. Determine its initial speed? (5.7m/s).​

Answer 1

Answer:

To solve typical question like this we have an equation

Explanation:

$s_{n} = u + \frac{a}{2} (2n - 1)$

u = initial velocity

a = gravitation acceleration downwards

n= nth time

eg: (4th, 5th)

$s_{n} = u + \frac{a}{2} (2n - 1) \\ 40 = u + \frac{10}{2} (2 \times 4 - 1) \\ u = 5m {s}^{ - 1}$