Home
Class 11
PHYSICS
A stone is dropped from a height h. Simu...

A stone is dropped from a height h. Simultaneously, another stone is thrown up from the ground which reaches a height 4 h. The two stones cross each other after time

A

`sqrt( (h)/(8g))`

B

`sqrt(8gh)`

C

`sqrt(2gh)`

D

`sqrt((h)/(2g))`

Text Solution

Verified by Experts

The correct Answer is:
A
For first stone u = 0
For second stone `(u^2)/(2g) = 4h rArr u^2 = 8gh`

` therefore u = sqrt(8gh)`
Now `h_1 = 1/2 g t^2`
`h_2 = sqrt(8ght) - 1/2 g t^2`
where, t =time to cross each other.
`because h_1 + h_2 = h`
`rArr 1/2 g t^2 + sqrt(8ght) - 1/2 g t^2 = h rArr t = (h)/(sqrt(8gh)) = sqrt( (h)/(8g))`
Promotional Banner

Similar Questions

Explore conceptually related problems

A stone is dropped from a height h. simultaneously, another stone is thrown up from the ground which reaches a height 4h. The two stones will cross each other after time:-

A stone is dropped from a height h. Simultaneously another stone is thrown up from the ground with such a velocity that it can reach a height of 4 h. Find the time when two stones cross each other.

A stone is dropped from a height h simultaneously another stone is thrown up from the ground with such a velocity so that it can reach a height of 4h. The time when two stones cross each other is sqrt(((h)/(kg))) where k = "_____"

A stone is dropped form 100 m high cliff. Another stone is thrown upward from ground with a velocity 10m/s. At what time both the stones will meet each other ?

In the previous problem, the height at which the two stones will cross each other is

A stone is dropped from the top of a 400 m high tower. At the same time another stone is projected vertically upwards from the ground with a speed of 50 m//s . The two stones will cross each other after a time

A stone is dropped from a height equal to nR , where R is the radius of the earth, from the surface of the earth. The velocity of the stone on reaching the surface of the earth is

One stone is dropped from a tower from rest and simultaneously another stone is projected vertically upwards from the tower with some initial velocity. The graph of distance (s) between the two stones varies with time (t) as (before either stone hits the ground).

A stone is dropped from the top of a tower of height h . Aftre 1 s another stone is droppped from the balcony 20 m below the top. Both reach the bottom simultaneously. What is the value of h ? Take g=10 ms^(-2) .