Question

A body is thrown vertically upword with an initial v4locity of 20m/sec×sec fron the ground find the speed of th3 ball when it reached half of maximum height (take g =10

Answer 1

$<b>Given that$

initial velocity of body = 20 m/s

g = $10 m/s^2$

to find the velocity at 1/2 H
we have to find out the height

Hence for height
$h = \frac{ {u}^{2} }{2g} \\ \\ = \frac{ {20}^{2} }{20} \\ \\ = \frac{400}{20} \\ \\ = 20m$
now as H max = 20m

then 1/2 H max = 10m

now from equation
${v}^{2} = {u}^{2} - 2gh \\ \\ {v}^{2} = {20}^{2} - 20 \times 10 \\ \\ {v }^{2} = 400 - 200 \\ \\ {v}^{2} = 200 \\ \\ or \: v = \sqrt{200} \\ \\ v = 10 \sqrt{2}$
$\red{\boxed{\green{Hope\:it\: helps}}}$