Question

A stone thrown vertically upwards from the top of a
tower with a velocity 20m/s reaches the ground in 6 s.
Find the height of the tower.

Answer 1

Answer:

Thrown vertically up with 20 m/s from top of the tower.

It reaches the ground in 6 seconds.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,u = 20 m/s.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,u = 20 m/s.v = 0 m/s.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,u = 20 m/s.v = 0 m/s.a = - 10 m/s^2.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,u = 20 m/s.v = 0 m/s.a = - 10 m/s^2.t = ?.

As the stone is thrown upward it will reach its highest point and at that point its velocity will be zero.Let it reaches highest point at time "t".Now,u = 20 m/s.v = 0 m/s.a = - 10 m/s^2.t = ?.From first kinematics equation.

v=u+at

t=v-u/a

t=20s

Now for free fall the time taken is

Now for free fall the time taken ist' = 6 - 2

Now for free fall the time taken ist' = 6 - 2t' = 4 seconds.

Now for free fall the time taken ist' = 6 - 2t' = 4 seconds.u = 0 m/s.

Now for free fall the time taken ist' = 6 - 2t' = 4 seconds.u = 0 m/s.a = 10 m/s^2.

Now for free fall the time taken ist' = 6 - 2t' = 4 seconds.u = 0 m/s.a = 10 m/s^2.S = H(Height of tower)

Now for free fall the time taken ist' = 6 - 2t' = 4 seconds.u = 0 m/s.a = 10 m/s^2.S = H(Height of tower)From second kinematic equation

(pic attached above)

H=80meters..