Physics: Post your doubts here!

[A*****]

Plz help

 

[Kanekii]

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12A since it can be clearly seen as the depth increases the magnitude of the pressure exerted increases.
29D The degree of diffraction increases as the narrower the slit/gap width gets and higher the wavelength gets. however since angle of diffraction is lower it must have lower degree of diffraction for this its wavelength needs to decrease and the slit width needs to get higher e.g 2x
wavelength= v/2f (inversely proportional to frequency)

 

[Kanekii]

Can someone explain this?

 

[A*****]

12A since it can be clearly seen as the depth increases the magnitude of the pressure exerted increases.

Why not C or D??

 

[A*****]

Can someone explain this?View attachment 64051

3 boxes = 0.006s
1 box= 0.006/3 = 0.002s = 0.002x 1000 = 2ms

 

[Kanekii]

Why not C or D??

For D pressure in sides is not increasing with depth and remains the same
For C the pressure of the top sides arrow is really low even when we know object is fully submerged so it should be greater as it already has higher depth.
Remember pressure exerted by water is in all directions.

 

[A*****]

For D pressure is not increasing with depth and remains the same
For C the pressure of the top sides arrow is really low even when we know object is fully submerged so it should be greater as it already has higher depth.
Remember pressure exerted by water is in all directions.

Do u mean the sideways pressure? It also increases with depth?

 

[Kanekii]

Do u mean the sideways pressure? It also increases with depth?

Yes, Precisely.

 

[A*****]

Can u plz answer 8 14 28 as well?

Yes, Precisely.

 

[Kanekii]

Can u plz answer 8 14 28 as well?

Is 28C?

 

[A*****]

Is 28C?

Yeah

 

[Kanekii]

Yeah

Oh didnt expect that honestly xD
Im not sure but i think both P and Q would have no path difference at RS and would only have at XY

 

[A*****]

Oh didnt expect that honestly xD
Im not sure but i think both P and Q would have no path difference at RS and would only have at XY

Oh well yesss this can be a possibility as the question asks about INTERFERENCE PATTERN, so it would only be visible at XY and at RS only constructive interference will occur...no destructive for the pattern
Righttt!

 

[Kanekii]

Something like this i assume

 

[Kanekii]

For Q 8 and 14 i have no clue

 

[A*****]

View attachment 64053 Something like this i assume

Yes I got it thanx alot!
Btw which path difference is this??

 

[A*****]

For Q 8 and 14 i have no clue

Its ok

 

[hellodjfos;s'ff]

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I'll do 14 first since it's easier. Take the axle as your pivot in this question. Now the issue with this question is that people don't understand where the 90N force is acting. I have attached a file to show where it's acting. The reason it's acting there is bc to move the vehicle forwards, there needs to be an anticlockwise moment so that the vehicle is pushed forwards. Now you know that all the forces and where they act, so just apply the principle of moment, clockwise moments=anticlockwise moments. Keep in mind that you don't where the man's weight will be acting when the vehicle applies a force, so that's what you will find in the calculation. This means: 600(200)=600(x)+90(400). You find that your x will be 140 mm. Since the man was initially standing 200 mm behind the axle and is now standing 140 mm behind it means that me moved 60 mm forwards making B the answer.

 

[hellodjfos;s'ff]

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8 is a slightly tougher question. Throughout this question, the balloon is moving at a constant speed meaning the balloon is in equilibrium so upwards forces must be equal to downward forces. In the first situation, the balloon is going down so the air resistance(AR) and upthrust(UT) are acting upwards while the weight(W) is acting downwards. This making an equation, W=AR+UT. The question states that the AR has a value of F. The final equation becomes W=F+UT. For the 2nd situation, the balloon goes up, hence the W and AR act downwards while UT acts up. The equation for the 2nd equation is UT=W+AR. Now replaced W with the equation you found in the 1st situation and AR with F(as the question says). UT=F+UT+F. If you solve this equation, you will find that it would be 0=2F. This means that there is a resultant force of 2F acting downwards, so to balance it you must either produce a force of 2F acting upwards or remove a force of 2F acting downwards. The question states how much weight must be released from the balloon, so that means weight of 2F must be removed. This makes B the answer. There could be alternative methods to solve this question but I find this one to be the best.

 

[dwightedknight]

8 is a slightly tougher question. Throughout this question, the balloon is moving at a constant speed meaning the balloon is in equilibrium so upwards forces must be equal to downward forces. In the first situation, the balloon is going down so the air resistance(AR) and upthrust(UT) are acting upwards while the weight(W) is acting downwards. This making an equation, W=AR+UT. The question states that the AR has a value of F. The final equation becomes W=F+UT. For the 2nd situation, the balloon goes up, hence the W and AR act downwards while UT acts up. The equation for the 2nd equation is UT=W+AR. Now replaced W with the equation you found in the 1st situation and AR with F(as the question says). UT=F+UT+F. If you solve this equation, you will find that it would be 0=2F. This means that there is a resultant force of 2F acting downwards, so to balance it you must either produce a force of 2F acting upwards or remove a force of 2F acting downwards. The question states how much weight must be released from the balloon, so that means weight of 2F must be removed. This makes B the answer. There could be alternative methods to solve this question but I find this one to be the best.

I can only dream of answering the questions that you find difficult .