ALL CIE PHYSICS DOUBTS HERE !!!

[Hypernova]

Okay, so I seem to be stuck on (b) [Refer to the attachment]. Would I use the equation "Phase angle = 2(pie)x/lambda"?

I don't know the DK's method, hopefully, he'll explain it to you.
This is what i do.

First find the amplitude of the second waveform.
We know that the intensity of the second wave is doulde the first,
So, 2I₁=I₂

Intesity is proportional to amplitude²

I₁=K x 5²                       I₂= K x a²

K=I₁/5²                   K= I₂/a²
                                                                  
now equate the two Ks

I₁/5² = I₂/a²
                          
using 2I₁=I₂, we say:  2= I₂/I₁
                                                                    
I₁/5² = I₂/a²
I₂/I₁ = a²/25
2  = a²/25
50 = a²
a = 7


Now draw the graph.
See I just know how to draw the graph. If the Wave has a hase difference of 180 degress, then it is completely out of phase,
If it is 90, then a 0.25 out of phase.

In other words. Look at the graph they gave you, 0.6 is one wavelength. So from 0 to O.6 is 360 degrees. so at 0.3, the phase angle of that point is 180 degrees. The new wave, when it starts from 0, will be in phase with the wave at this point.
So my wave looks like the one attached.

[$!$RatJumper$!$]

All that work for 2 marks wow Cambridge sucks lol

[$!$RatJumper$!$]

W03 P2 Q 3 (c) (ii) 2, why is the torque the same as the moment? I thought torque was calculated by the equation:
Torque = Force * Perp Distance between two forces

[Hypernova]

Torque and moment is essentially the same, both being the turning effect of a force

a 'moment' is called 'torque' when it involves a couple.

Look at this

Torque = Force * Perp Distance between two forces         
Torque= Force x (Perp Distance between pivot x 2)
Torque= 2 x Force x Perp Distance between pivot


Moment = Force₁ x Perp Distance between pivot + Force₂ x Perp Distance between pivot      (Since F₁=F₂)
Moment= 2 x Force x Perp Distance between pivot


There is no difference bettween them, just the definition.

[$!$RatJumper$!$]

Torque and moment is essentially the same, both being the turning effect of a force

a 'moment' is called 'torque' when it involves a couple.

Look at this

Torque = Force * Perp Distance between two forces        
Torque= Force x (Perp Distance between pivot x 2)
Torque= 2 x Force x Perp Distance between pivot


Moment = Force₁ x Perp Distance between pivot + Force₂ x Perp Distance between pivot      (Since F₁=F₂)
Moment= 2 x Force x Perp Distance between pivot


There is no difference bettween them, just the definition.

Thank you that makes a lot of sense

Another question, S04 Q 4 (b)(i), what is the direction of the force?

[Hypernova]

Thank you that makes a lot of sense

Another question, S04 Q 4 (b)(i), what is the direction of the force?

Upward

Use Newton's Third law: To every action there is always an equal and opposite reaction: or the forces of two bodies on each other are always equal and are directed in opposite directions.

Basically, The Ball exerts a downward force on the ground, so the ground will exert an equal force but opposite in direction (upward) on the ball.

[$!$RatJumper$!$]

gr8 thankx +rep

[Hypernova]

gr8 thankx +rep

I assumed that you were you ok with finding its magnitude. Should I do it?

[$!$RatJumper$!$]

yea u assumed right haha

[TJ-56]

Im finding it difficult to 'spread the love' deadly king, i will +rep the moment i can do so,
I have a question, regarding a drawing again pls
November 2005 paper 2 q8 (b) (ii) (last question)
can you draw it for me pls? the mark scheme is rly confusing me
thank you so much

[$!$RatJumper$!$]

Im finding it difficult to 'spread the love' deadly king, i will +rep the moment i can do so,
I have a question, regarding a drawing again pls
November 2005 paper 2 q8 (b) (ii) (last question)
can you draw it for me pls? the mark scheme is rly confusing me
thank you so much

The equation for Gravitational Potential Energy is: mgh. Now it says that a ball is falling vertically through the air. Which means, that it was initially dropped mid air and is thus falling towards the ground.

From this we can conclude that since it is falling towards the ground, its height above the ground is decreasing as it falls closer. We also know that the mass "m" of the ball and the gravitational feild strength "g" are constant and do not change. So the only thing changing is the value of "h" in the equation. Since it is decreasing and everything else staying constant, the value for the Gravitational Potential Energy will decrease as a result.

This is why the mark scheme says negative gradient because the value for Gravitational Potential Energy is decreasing. Since it was at its maximum height when it was dropped, it will have maximum Gravitational Potential Energy thus the line starts at the maximum y intercept above E_k and ends at h₀ on the x-axis.

[TJ-56]

The equation for Gravitational Potential Energy is: mgh. Now it says that a ball is falling vertically through the air. Which means, that it was initially dropped mid air and is thus falling towards the ground.

From this we can conclude that since it is falling towards the ground, its height above the ground is decreasing as it falls closer. We also know that the mass "m" of the ball and the gravitational feild strength "g" are constant and do not change. So the only thing changing is the value of "h" in the equation. Since it is decreasing and everything else staying constant, the value for the Gravitational Potential Energy will decrease as a result.

This is why the mark scheme says negative gradient because the value for Gravitational Potential Energy is decreasing. Since it was at its maximum height when it was dropped, it will have maximum Gravitational Potential Energy thus the line starts at the y intercept and ends at h₀.

thanx +rep that cleared it up
just one last point, why does it start from above the maximum kinetic energy as stated on the ms?

[$!$RatJumper$!$]

Thankx for the +rep

It starts above because it has the maximum possible gravitational energy when it is at its maximum point just as it is released. The point is, that you need to start your negative sloping line right at the top of the y-axis just to show the examiner that you understand it is at its maximum energy initially. It has to have nothing to do with the kinetic energy because they are separate things. Yes, they are related, but not in such a way that they need to start at the same point.

[TJ-56]

Thankx for the +rep

It starts above because it has the maximum possible gravitational energy when it is at its maximum point just as it is released. The point is, that you need to start your negative sloping line right at the top of the y-axis just to show the examiner that you understand it is at its maximum energy initially. It has to have nothing to do with the kinetic energy because they are separate things. Yes, they are related, but not in such a way that they need to start at the same point.

thanx alot, i finally got it!

[$!$RatJumper$!$]

Im glad