Question

A ball is dropped for a top of a town when it has fallen by a t m from the top another ball b is dropped from a point 120 M below the top if the both the balls reach the ground at the same moment then the height of the tower will be​

Answer 1

Answer:

Let the first ball reaches the ground after time t, the second ball will take time (t−2).

80=12gt2⇒t=4s

Let u: initial velocity of the second ball

80=u(t−2)+12g(t−2)2

=u(4−2)=12×10(4−2)2

=2u+20

u=30m/s