A-ball-is-thrown-vertically-upward-with-velocity-20-m-s-from-a-rail-road-car-moving-with-a-velocity-5-m-s-horizontally-A-person-standing-on-the-ground-observes-its-motion-as-projectile-Find-maximum-

Question Number 15407 by Tinkutara last updated on 10/Jun/17

A ball is thrown vertically upward

with velocity 20 m / s from a rail road

car moving with a velocity 5 m / s

horizontally . A person standing on the

ground observes its motion as projectile .

Find maximum height attained by the

ball if point of projection is at a height

3 m from the ground .

Answered by mrW1 last updated on 10/Jun/17

y = 3 + 20 t - \frac{1}{2} \times {10 t}^{2} = 3 + 20 t - {5 t}^{2}

= 23 - 5 (t^{2} - 4 t + 4) = 23 - 5 {(t - 2)}^{2} ⩽ 23

\Rightarrow \max . height = 23 m

Commented by Tinkutara last updated on 10/Jun/17

Thanks Sir!