Question

a stone is allowed to fall from a building of height 30 meters. the ratio of heights fallen by it after 2 seconds and 3 seconds is​

Answer 1

Answer:

Let the stones meet at point A after time t.

For upper stone :

u

′

=0

x=0+

2

1

gt

2

x=

2

1

×10×t

2

⟹x=5t

2

............(1)

For lower stone :

u=25 m/s

100−x=ut−

2

1

gt

2

100−x=(25)t−

2

1

×10×t

2

⟹100−x=25t−5t

2

............(2)

Adding (1) and (2), we get

25t=100

⟹t=4 s

From (1),

x=5×4

2

⟹x=80 m

Hence the stone meet at a height of 20 m above the ground after 4 seconds.