# Thought Of The Day_4_Work N Frames!!

$$Comments Invited!!$$

Note by Rohit Gupta
3 years, 1 month ago

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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)

It is clear work done is negative.

- 3 years, 1 month ago

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

- 3 years, 1 month ago

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

- 3 years, 1 month ago

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.

- 3 years, 1 month ago

Bhiya Can U give me ur Email ID ?

- 3 years, 1 month ago

Comment deleted May 22, 2015

Comment deleted Jul 08, 2015

The problems are a little easy and it seems like lol and troll ( when he says he himself has not solved )

- 3 years, 1 month ago

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..!!

- 3 years, 1 month ago

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

- 3 years, 1 month ago

Opps My bad... Sry for misunderstanding..!! And all the best for you Advance test..!!

- 3 years, 1 month ago

Comment deleted Jul 08, 2015

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.

- 3 years, 1 month ago

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

- 3 years, 1 month ago

I thought you already saw it , anyways click on my profile.

- 3 years, 1 month ago

Thank You Bhiya. Your problems are great! You would surely get AIR 1.

- 3 years, 1 month ago

W=F.S when force is constant.
As clearly seen from diagram,angle b/w force and displacement is 90.
Hence, work done is 0

- 3 years ago

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

- 3 years ago

Can you see this ?

- 3 years ago

Comment deleted Jul 08, 2015

Then how come wedge is getting the kinetic energy??

- 3 years, 1 month ago

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.

- 3 years, 1 month ago

Even I thought the same.

- 3 years, 1 month ago

weight

- 3 years, 1 month ago

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..!!!

- 3 years, 1 month ago

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.

- 3 years, 1 month ago