Two balls of equal mass are projected upwards simultaneously, one from the ground with initial velocity `50ms^-1` and the other from a `40m` tower with initial velocity of `30ms^-1`. The maximum height attained by their COM will be

Answer

100m

Explanation

`u_(CM)=(m(30)+m(50))/(2)=40m//s`
`h_(i)=20m`
`h_(f)-h_(i)=h(u_(CM)^(2))/(2g)=(40xx40)/(20)=80m`
`h_(f)=100m`