Question

a boy throws a stone straight upward with an initial velocity of 5 m/s from the surface of the earth. What is the maximum height above the starting point will the stone reach before it starts back?

Answer 1

Answer:

The initial velocity of the stone thrown from the cliff is 5 m/s

The stone strikes the pond near the base after 4 sec.

The stone moves in upward direction initially and then after reaching a maximum height, it starts to come down and reaches the base of the cliff.

In overall motion of the stone, the net displacement in the opposite direction of the initial velocity.

S=ut−

2

1

at

2

Substitute the values in above expression:

S=(5×4)−

2

1

×10×4

2

S=20−80=−60 m

So, the height of the cliff is 60 m.