Question

A ball is dropped from the roof of a tower of height h.The total distance covered by it in the last second of its motion is equal to the distance covered by it in first three seconds.The value of h in metre is?

Answer 1

Answer: here the ball is dropped from the tower.

Therefore, initial velo(u) =0

t =3 sec

Now distance covered in 3 seconds is given by

S=ut+ (1/2)gt^2

=0*3+(1/2)×10*3^2

=45m

By question, S( in 3 seconds)= height of tower

Therefore, h =45m