Since normal( Between block and wedge) is not a dissipative force hence net work done by it on the system is zero.

Now the lower wedge is getting velocity because of the normal force hence it is doing positive work on the wedge , since net work is zero it implies normal force does negative work on the block.

Ans) Negative

Another way to analyse the FBD of the block

The normal force is making an angle \theta with the positive y-axis and the block's displacement has two components one perpendicular to block and one along the -x axis. So work done in first component is zero and work done in second component is -Nxsin(\theta) ( The angle between normal and displacement(x) is 90+\theta)

@Ronak Agarwal
–
My Aim here is not to put such problems that no one is able to solve...But to put conceptual problems....And I have never claim that i was not able to solve them..
Problems are not grt There Solutions Are..!!

@Rohit Gupta
–
Sorry I was not talking about you, Rohit Sir Check the link Given by Rajdeep, there a child has created some problems I was talking about him,these conceptual problems are good Sir

@Rajdeep Dhingra
–
But you solved all my mechanics problems very very easily I see you in solvers list of my every problem, It simply proves you are quite intelligent in physics, you see I have recently released part 4 of my challenges in mechanics.

@Rajdeep Dhingra
–
For increase in kinetic energy of wedge some force must do work on wedge..!! which force is doing work on wedge?? weight of wedge or weight of block..
weight of wedge can't do work on wedge as its displacement is perpendicular to the force and weight of block cant do work on wedge either as it is not acting on wedge it is acting on block..!!!

@Rohit Gupta
–
sir i wrote in my comment above, if it is wrong then i don't know the answer but one component of the weight of the block will act on the wedge.

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## Comments

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TopNewestSince normal( Between block and wedge) is not a dissipative force hence net work done by it on the system is zero.

Now the lower wedge is getting velocity because of the normal force hence it is doing positive work on the wedge , since net work is zero it implies normal force does negative work on the block.

Ans) Negative

Another way to analyse the FBD of the block

The normal force is making an angle \theta with the positive y-axis and the block's displacement has two components one perpendicular to block and one along the -x axis. So work done in first component is zero and work done in second component is -Nxsin(\theta) ( The angle between normal and displacement(x) is 90+\theta)

It is clear work done is negative.

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Yes You are Right Here..!! Kudos..!!

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Best of luck Bhaiya for Sunday. I am sure U will get AIR 1. \(\ddot\smile\)

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If by chance I would get a rank just under 100 I would be over the moon and you are talking about 1 Ha Ha Ha.

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Bhiya Can U give me ur Email ID ?

Please Respond.

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@Ronak Agarwal -please give me link, i cant see any new mechanics problems by you?

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W=F.Swhen force is constant.As clearly seen from diagram,angle b/w force and displacement is 90.

Hence, work done is 0

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@Akhil Bansal I am sorry but the angle between force and displacement here is not 90..!!

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Can you see this ?

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Then how come wedge is getting the kinetic energy??

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the weight of the block is divided into two components. one gives it velocity along the wedge and the other is perpendicular onto the wedge.

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weight

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weight of wedge can't do work on wedge as its displacement is perpendicular to the force and weight of block cant do work on wedge either as it is not acting on wedge it is acting on block..!!!

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