Q.
When a ball is thrown up vertically with velocity v0, it reaches a maximum height of h. If one wishes to triple the maximum height then the ball should be thrown with velocity:
At maximum height velocity is zero.
From equation of motion we have v2=u2−2gh
where v is final velocity, u is initial velocity. Since ball reaches maximum height, velocity at the highest point is zero. Therefore, we have v=0,u=v0 ⇒v0=2gh
when h′=3h then v0′=2g×3h=32gh=3v0