An elevator platform is going up at a sp...

An elevator platform is going up at a speed of `20 m//s` and during its upward motion a small ball of `50 g` mass, falling in downward direction, strikes the platform at speed `5 m//s`. Find the speed with which the ball rebounds.

Text Solution

Verified by Experts

The situation is analysed in the figure. There we can consider mass of platform to be very large compared to that of the ball so we have
`vecv_(1)=vecu_(1)` and `vecv_(2)=2vecu_(1)-vecu_(2)`
Thus rebound velocity of the ball is
` vecv_(2)=2xx20-(-5)=45m//s` upward

Topper's Solved these Questions

CENTRE OF MASS
CENGAGE PHYSICS|Exercise Subjective|23 Videos
CENTRE OF MASS
CENGAGE PHYSICS|Exercise Single Correct|141 Videos
CENTRE OF MASS
CENGAGE PHYSICS|Exercise Exercise 1.2|23 Videos
CALORIMETRY
CENGAGE PHYSICS|Exercise Solved Example|13 Videos
DIMENSIONS & MEASUREMENT
CENGAGE PHYSICS|Exercise Integer|2 Videos

Similar Questions

Explore conceptually related problems

An elevator platform is going up at a speed 20 ms^(-1) and during its upward motion a small ball of 50 g mass falling in downward direction strikes the platform elastically at a speed 5 ms^(-1) . Find the speed (in ms^(-1) ) with which the ball rebounds.

A ball is thrown up at a speed of 4.0 m/s. Find the maximum height reached by the ball. Take g=10 m//s^2 .

A highly elastic ball moving at a speed of 3 m//s approaches a wall moving towards it with a speed of 3 m//s . After the collision. the speed of the ball will be

A ball moving vertically downward with a speed of 10 m//s collides with a platform. The platform moves with a velocity of 5 m//s in downward direction. If e = 0.8 , find the speed (in m//s ) of the ball just after collision.

A ball falls from a height of 5 m and strikes a lift which is moving in the upward direction with a velocity of 1 m s^(-1) , then the velocity with which the ball rebounds after collision will be

Two balls are projected vertically upward with same speed 35 m/s in 3s interval. Find height at which both balls collide.

A platform is moving upwards with a constant acceleration of 2 m s^-2 . At time t = 0 , a boy standing on the platform throws a ball upwards with a relative speed of 8 m s^-1 . At this instant, platform was at the height of 4 m from the ground and was moving with a speed of 2 m s^-1 . Take g = 0 m s^-2 . Find (a) when and where the ball strikes the platform. (b) the maximum height attained by the ball from the ground. ( c) the maximum distance of the ball from the platform.

A body falling with a speed of 2m/s strikes the floor and rebounds with a speed of 1 m/s. The loss of kinetic energy is

A ball is thrown up with a speed of 15 m//s . how high will it go before it begins to fall ? Take g=9.8 m//s^(2) .

CENGAGE PHYSICS-CENTRE OF MASS-Exercise 1.3

A ball is dropped on a floor from a height h. If the coefficient of re...
Text Solution
|
An elevator platform is going up at a speed of 20 m//s and during its ...
Text Solution
|
A ball of mass m is distributed from the top of a fixed smooth circula...
Text Solution
|
A particle of mass 1 kg is attached to a string of length 5 m. The str...
Text Solution
|
A heavy ball of mass 2M moving with a velocity v(0) collides elastical...
Text Solution
|
In Fig. there are n identical suspended with wires of equal length. Th...
Text Solution
|
A smooth sphere of mass m is moving on a horizontal plane with a veloc...
Text Solution
|
Two smooth spheres. A and B. having equal radii, lie on a horizontal t...
Text Solution
|
A block m(1) strikes a stationary block m(3) inelastically. Another bl...
Text Solution
|
A mass m(1) moves with a great velocity. It strikes another mass m(2) ...
Text Solution
|
A ball of mass 4 kg moving with a velocity of 12 m//s impinges directl...
Text Solution
|
A bullet of mass 2 g travelling at a speed of 500 m//s is fired into a...
Text Solution
|
A 3.00 kg steel hall strikes the wall with a speed of 10.0 m//s at an ...
Text Solution
|
A spherical imperfectly elastic ball strikes a plane with velocity 8 m...
Text Solution
|
Three balls of masses m(1), m(2) and m(3) are lying in a straight line...
Text Solution
|
Two identical balls A and B lie on a smooth horizontal surface, which ...
Text Solution
|
A smooth ball of mass m is suspended from a light string of length 1 m...
Text Solution
|
Three particles A, B and C of respective masses m(1), m(2) and m(3) li...
Text Solution
|
A ball moving along a straight line collides elastically with another ...
Text Solution
|
A machine gun can fire bullets of 50 grams at a Speed of 2000 m s^(-1)...
Text Solution
|