Physics: Post your doubts here!

[shinnyyy]

Uhm..wait lemme try
I couldnt do the density qtn ill try the other 1

I have tried to solve that density one but idk what I'm doing in that question, can u plz check one that too cz it's repeated thrice in p.p

 

[Wkhan860]

I have tried to solve that density one but idk what I'm doing in that question, can u plz check one that too cz it's repeated thrice in p.p

I have tried it 3 times nd got it wrong every time

 

[shinnyyy]

I have tried it 3 times nd got it wrong every time

Haha then hi5
even my sir couldn't solve that tch tch
But what about the other one ?? Idk why they have shown a force coming out of the pivot, I don't think so if I have studied any such thing from the coursebook.

 

[Wkhan860]

Haha then hi5
even my sir couldn't solve that tch tch
But what about the other one ?? Idk why they have shown a force coming out of the pivot, I don't think so if I have studied any such thing from the coursebook.

Actually my sir did solve tht qtn but i forgot the method
Its 'C' I thnk....its a fluke tbh...T will be greatest as u need force greater than doors 'W' to move it..no idea abt 'H'
Or use the triangle of force method

 

[Liv2Stdy]

View attachment 55140 q21?

The pressure at the bottom is given. This is the sum of the pressures at the bottom of the layer of oil and at the bottom of the layer of water. So all you need to do is add these two pressures. If you dont get it, I'll be happy to explain it further. Answer is D.

 

[shinnyyy]

The pressure at the bottom is given. This is the sum of the pressures at the bottom of the layer of oil and at the bottom of the layer of water. So all you need to do is add these two pressures. If you dont get it, I'll be happy to explain it further. Answer is D.

View attachment 55170

Oh I got it ..tysm
And can you plz explain me the other question aswell?

 

[shinnyyy]

Actually my sir did solve tht qtn but i forgot the method
Its 'C' I thnk....its a fluke tbh...T will be greatest as u need force greater than doors 'W' to move it..no idea abt 'H'

Sorry still I didn't get that :/

 

[Liv2Stdy]

Oh I got it ..tysm
And can you plz explain me the other question aswell?

Hi, which one?

 

[shinnyyy]

There's another question from forces unit :
If a car is moving in a horizontal direction then in which direction the net force will act on the car.secondly how we'll draw the vector diagram for this question.

This one

 

[shinnyyy]

View attachment 55142 How we have to solve this question and what's the logic behind the ans.

And this one

 

[Liv2Stdy]

And this one

OK so I'm not a 100 percent sure of this but If I'd been given to solve this, I would do it this way.

First you need to break T and H into components and then construct two equations saw that everything you see on the diagram is balanced.
Then its more or less a guessing game.


As you can see, the vertical component of T is balanced by both the vertical component of H and W.
The value of W would be the vertical component of T minus Vertical component of H.....mind you these are the components of forces we are talking about so obviously the value of W will be the smallest.
While the horizontal components of the two forces are equal, the vertical component of H is still smaller (vertical component of T - W), so we can assume that the magnitude of H is smaller than T.

So in the increasing order, the forces would be W, H, T. Answer is C.

Is it correct?

 

[Liv2Stdy]

This one

Is this the full question?

 

[shinnyyy]

Is this the full question?

Yeah it is ..actually it was some mcq and I have copied it's wording but idk the concept behind that

 

[Liv2Stdy]

Yeah it is ..actually it was some mcq and I have copied it's wording but idk the concept behind that

Well, I can tell you this much, If the car is "moving" in a certain direction, it means it has overcome frictional forces and air resistance, so the resultant force would be in the direction of the movement of the car.
As for the vector diagram, I have no idea...atleast not yet!lol. I might need to sit on that for a while and see. Sorry.

 

[shinnyyy]

Wkhan860 can you plz check this and lemme know if I have done it correctly, though I have multipled it by s but idk why I did that :/
Thanks in advance for the assistance

 

[shinnyyy]

Physicist can u plz solve the question which I have posted above?

 

[shinnyyy]

OK so I'm not a 100 percent sure of this but If I'd been given to solve this, I would do it this way.

First you need to break T and H into components and then construct two equations saw that everything you see on the diagram is balanced.
Then its more or less a guessing game.
View attachment 55171

As you can see, the vertical component of T is balanced by both the vertical component of H and W.
The value of W would be the vertical component of T minus Vertical component of H.....mind you these are the components of forces we are talking about so obviously the value of W will be the smallest.
While the horizontal components of the two forces are equal, the vertical component of H is still smaller (vertical component of T - W), so we can assume that the magnitude of H is smaller than T.

So in the increasing order, the forces would be W, H, T. Answer is C.

Is it correct?

Yeah the ans is C. Thanks alot

 

[Wkhan860]

View attachment 55172 Wkhan860 can you plz check this and lemme know if I have done it correctly, though I have multipled it by s but idk why I did that :/
Thanks in advance for the assistance

Work=F*displacement
So in this case the total force applied is Fs
While the force opposing the motion is component of weight mgsin(â)......the work done by th opposing force will be mgsinâ*s
Thn use efficiency formula mgsinâ*s/Fs.....s gets cancelled...whch gives D

 

[shinnyyy]

Work=F*displacement
So in this case the total force applied is Fs
While the force opposing the motion is component of weight mgsin(â)......the work done by th opposing force will be mgsinâ*s
Thn use efficiency formula mgsinâ*s/Fs.....s gets cancelled...whch gives D

How a force can be equal to Fs
and why we have multiplied that component with s ?though I did that with heat and trial method but I have no concept for this.

 

[Wkhan860]

How a force can be equal to Fs
and why we have multiplied that component with s ?though I did that with heat and trial method but I have no concept for this.

Its nit the force tht is Fs
Its work....we r finding efficiency of work
Thts y Force *displacement