Question

When a body is projected vertically upward find velocity when it reaches half of the maximum height that is 10 metres

Answer 1

Answer:

since the half of max. height is 10, therefore the max. height is 20.

now let , s=20 ,v=0 ,g=-10 ,u=?...

therefore by- v^2 = u^2+2as

0=u^2 + 2 × -10 × 20

= u^2 + 400

u = 20 m/a

again , for s= 10

v^2= u^2 + 2as

=20^2 +2 × -10 × 10

=200

v = 4 /sqrt{5} m/s