Question

A man throws a stone vertically down from a height with an initial velocity = -5 m / s . After 3 seconds , the stone reaches the ground ( at point A ) . What is the height h ?

Answer 1

Given:

The initial velocity of the stone, v₀=-5 m/s

The time it takes for the stone to reach the ground, t=3 s

To find:

The height.

Step-by-step explanation:

From the equation of motion,

`-h=v_0t-(1)/(2)gt^2`

On substituting the known values,

`\begin{gathered} -h=-5*3-(1)/(2)*9.8*3^2 \\ \Rightarrow-h=-60 \\ \Rightarrow h=60\text{ m} \end{gathered}`

Final answer:

The height from which the