Home
Class 11
PHYSICS
A block of mass m is kept on a platform ...

A block of mass m is kept on a platform which starts from rest with constant acceleration g/2 upward, as shown in fig. Work done by normal reaction on block in time t is :

A

`(m g^(2)t^(2))/(8)`

B

0

C

`- (m g^(2) t^(2))/(8)`

D

`(3m g^(2) t^(2))/(8)`

Text Solution

Verified by Experts

The correct Answer is:
D
`N- mg = (mg)/(2)`
`N= (3mg)/(2)`
`s= u t+ (1)/(2) a t^(2)`
`=0 + (1)/(2) (g)/(2)(t)^(2)= (g)/(4) t^(2)`
`W_(N)`= Force `xx` Displacement `= (3mg)/(2) xx (g t^(2))/(4)`
`rArr (3mg^(2) t^(2))/(8)`
Promotional Banner

Similar Questions

Explore conceptually related problems

A block of mass m is kept on a platform which starts from rest with constant acceleration g/4 upward, as shown in the figure. Work done by normal reaction on block in time t is:

A block of mass M is kept on a platform which is accelerated upward with a constant acceleration 'a' during the time interval T. The work done by normal reaction between the block and platform is

A block of mass m is kept on a platform Platform starts moving upwards with an acceleration of g/2 . Find the work done by the normal force on the block in the first one second.

A block of mass M is kept on a platform which starts accelerating upwards from rest with a constant acceleration a. During the time interval T, the work done by contact froce on mass M is (##NAR_NEET_PHY_XI_P2_C06_E09_011_Q01##)

A block of mass M is kept in elevator (lift) which starts moving upward with constant acceleration b as shown in figure. Initially elevator at rest. The block is observed by two observers A and B for a time interval t=0 to t=T . Observer B is at rest with respect to elevator and observer A is standing on the ground. Q. The observer A finds that work done by normal reaction acting on the blocks is

A block of mass M is kept in elevator (lift) which starts moving upward with constant acceleration b as shown in figure. Initially elevator at rest. The block is observed by two observers A and B for a time interval t=0 to t=T . Observer B is at rest with respect to elevator and observer A is standing on the ground. Q. The observer A finds that the work done by gravity on the block is

A block of mass M is kept in elevator (lift) which starts moving upward with constant acceleration b as shown in figure. Initially elevator at rest. The block is observed by two observers A and B for a time interval t=0 to t=T . Observer B is at rest with respect to elevator and observer A is standing on the ground. Q. According to observer B

A block of mass m is kept in an elevation which starts moving downward with an acceleration 'a' as shown in figure. The block is observed by two observers A and B for a time interval t_(0) . . The observer B finds that the work done by gravity on the block is :

A block of mass m is kept in an elevation which starts moving downward with an acceleration 'a' as shown in figure. The block is observed by two observers A and B for a time interval t_(0) . . According to observer B , the net work done on the block is :

A block of mass m is kept in an elevation which starts moving downward with an acceleration 'a' as shown in figure. The block is observed by two observers A and B for a time interval t_(0) . . The observer B finds that the work done by pseodo-force on the block is