Question

A ball falls off a table and reaches the ground in $1s$. Assuming $g=10m/s^2$, calculate its speed on reaching the ground and the height of table.

Answer 1

Initial velocity $u=0$ Let final velocity is $v$ and height is $h$.

Using $v=u+at$

$\Rightarrow v=0-10\times 1=-10m/s$

Using $s=ut+\frac{1}{2}a{t}^2$

$\Rightarrow -h=0\times 1-\frac{1}{2}\times 10\times 1^2$ $\Rightarrow h=5m$