Physics: Post your doubts here!

[The Godfather]

Question 24 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf

if frequency is halved, the period is doubled as f=1/T
--> time taken for 1 complete cycle is doubled

intensity ∝ (amplitude^2)
amplitude ∝ √intensity

if intensity is doubled, thus the new amplitude is √2= 1.4
isilye B

 

[The Godfather]

thank you sooo sooo much!

WELCOME

 

[The Godfather]

Question 26 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s04_qp_1.pdf

http://www.physicsforums.com/showthread.php?t=403570

 

[The Godfather]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_12.pdf

28 please

Phase diff of 1 wavelengeth is 2pi tht is 360 degree so x to y is 270 deg

 

[Ahmed Aqdam]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s04_qp_1.pdf
Q9 Ans is D
http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s09_qp_1.pdf
Q18 Ans is D
Q19 Ans is A

 

[huh]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_11.pdf
Really need

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_12.pdf

In question 26, why is the answer D?

The breaking force isn't the same for both. There's a minor difference.

The first curve is brittle, the second one isn't.
The second one doesnt obey Hooke's Law.
The first one is elastic not plastic, because force is proportional to extension.
The last one is the answer because both curves have equal peaks. Peak = Ultimate tensile stress.

Hope this helped.

 

[ashcull14]

oh

I did it like this, on the first sight
View attachment 44896

oh silly me thnks

 

[ashcull14]

t

0.7 m --------- 1.1 V So,
0.9 m ---------- ?

Cross multiply, you get V = 1.4

hnks

 

[Asad Moosvi]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_12.pdf

Questions 8, 10, 23 and 28 please!

In question 8, why can it not be B? It does start from rest.

 

[Princess Raven]

Can someone tell me what each of these letters represent coz a lot of questions with the same graphs come inn different papers and I keep getting them wrong plz

 

[ShreeyaBeatz]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s13_qp_11.pdf
Q.No. 17, 14, 35,39 and 37
Someone please

 

[Ahmed Aqdam]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_12.pdf

Questions 8, 10, 23 and 28 please!

8: The velocity is constant for the first part and the second part but both are different. So acceleration is not constant. Also, there is no evidence that speed is zero at the start so B is wrong. Its not a straight line so distance is not proportional. Speed changes so D.

10: At X, sand is stationary and truck is moving so when they stick together the speed decreases.
At Y, sand also leaves with some speed and as the total mass remains same, the speed will not change.

23: Elastic potential or strain energy is calculated by area under force-extension graph. This is greatest in B.

 

[selena]

 

[selena]

 

[Asad Moosvi]

8: The velocity is constant for the first part and the second part but both are different. So acceleration is not constant. Also, there is no evidence that speed is zero at the start so B is wrong. Its not a straight line so distance is not proportional. Speed changes so D.

10: At X, sand is stationary and truck is moving so when they stick together the speed decreases.
At Y, sand also leaves with some speed and as the total mass remains same, the speed will not change.

23: Elastic potential or strain energy is calculated by area under force-extension graph. This is greatest in B.

I don't understand what happens at Y in question 10. The total mass of what remains the same? The sand falls away, so the total mass should be less.

 

[Ahmed Aqdam]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s13_qp_11.pdf
Q.No. 17, 14, 35,39 and 37
Someone please

14: Moment is calculated by force*distance so they are inversely proportional. B is the correct graph for this.

17 and 35

37. When resistance is zero, p.d. will be zero and current passing thorugh the circuit will be maximum due to low resistance.
When resistance is maximum, p.d. will be maximum but current will not be zero as some current passes through.

39. Few particles will bounce back as most of the mass is concentrated at a point so a head-on collision only will result in this which has a low probability.

 

[Ahmed Aqdam]

I don't understand what happens at Y in question 10. The total mass of what remains the same? The sand falls away, so the total mass should be less.

The mass of the truck is less but total mass of the system is same. The sand will also leave with speed and will not be stationary when thrown out.

 

[Ahmed Aqdam]

View attachment 44956

Convert the height into meters which will be 0.8m and apply the formula Pressure=p*g*h

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf
Q9. How to solve it? If using scale factor, how to convert percentage to scale factor?

 

[JutniP]

stuck on question 20.The correct answer is D but I have absoutely no clue how to do this.Its Physics paper 12 mayjune 13.please help me out someone!