# Physics: Post your doubts here!

Discussion in 'International A And AS Level' started by XPFMember, Sep 29, 2011.

1. ### Physicist

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3. ### Physicist

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go to
http://physics-ref.blogspot.com/2018/09/a-man-travels-on-toboggan-down-slope.html

4. ### troller

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Guyz i need some tips from you people...I will be giving maths and chemistry Accel in 19 may/june along with physics A2.......Please tell me when should i start preparing FOR AS syllabus as i have studied it last year.......And please give me tips how can i get best grades?

5. ### Physicist

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go through the questions at
http://physics-ref.blogspot.com/

6. ### troller

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Please tell me is it useful to Solve question given in DAVID SANG(PHYSICS ALEVEL BOOK)?what are the benefits of solving this??

7. ### Jihoo Lee

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Hi guys.
Do I need to get A in every papers to get A* in total? My friend said that don't need to get every paper(1 to 5) to get an A, but to get an A*, I should not have any B or C in my component. Is he correct?

8. ### studyingrobot457

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it depends on the total mark,
e.g
in m/j 2018, The threshold for A* in physics was 203/260
this was for p11,21,31,41,51

so let's suppose u g0t the following marks
p1 38/40 - which is A for the component
p2 28/60 - which is C for the component
p3 - 32/40 -which is A for the component
p4 - 92/100 -which is A for the component
p5 - 13/30 - which is C for the component

total : 203

thus u get A*

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9. ### hellodjfos;s'ff

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I have the book. The book is good for revision of most topics, but the questions in the book are really easy so no point in doing them. Go straight to past paper questions instead.

10. ### hellodjfos;s'ff

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No, you don't need an A in every paper to get an A*. You may have a D in a component and still achieve an A*(of course that requires you to score exceptionally well in the other components). If you look at the grade thresholds for physics, you need to get a raw score of 177 to get an A and 203 for A* out of 260.

11. ### studyingrobot457

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12. ### hellodjfos;s'ff

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Haha relax dude, just tryna help out. I didn't even see your reply

13. ### ZHANG XIN

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Can someone provide an explanation to part (b) of this question?

I'm confused by magnitude of gravitational potential. Gravitatioanl potential is a scalar quantity and it is always negative.
If scalar quantity has magnitude only, the magnitude of gravitational is also a negatvie value.

In the the examiner report, the magnitude of gravitational potential is a positive value. so the answer is Ep = -mφ

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14. ### Wâlèé Atèéq

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Can I get Topical P4 compiled with MS ?

15. ### VinSmoke

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In p3 i haven't made the table outline, but have recorded all data. How much marks am i loosing?

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0. You weren't going to get outline marks, just make sure rows and columns are identifiable!

17. ### Raheel327

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Q. A car of mass 1.2×10^3 kg travels along a horizontal road at a speed of 10 m/s. It then accelerates at 0.20 ms-2. At the time it begins to accelerate, the total resistive force acting on the car is 160 N. What total output is developed by the car as it begins the acceleration? A. 0.80 kW B. 1.60 kW C. 2.4 kW D. 4.0 kW.

Q. A railway locomotive pulling a train delivers a constant power of 2.0×10^6 W to the wheels. The resistive forces are constant at all speeds. The maximum speed that the train can achieve on a level track is 40 ms-1. What is the resultant force accelerating the train when it is traveling at 10 ms-1?
A. 5.0 kW B. 5.5 kW C. 20 kW D. 22 kW

18. ### Hamnah Zahoor

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F - R = ma
F - 160 = (1.2*10^3) (0.20)
F = 400

P = Fv
P = (400)(10)
p = 4000 W
P = 4.0 kW ( option D)

19. ### Hamnah Zahoor

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What is the answer for the above question?
And I guess you have typed in the question wrong because the question asks for the resultant force but the units used in the option are for power.

20. ### Raheel327

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Its D, 4.0 kW.
The correct second question options:
A. 5.0×10^4 N B. 1.5×10^5 N C. 2.0×10^5 N
D. 2.5×10^5 N
1.5×10^5 N is the correct answer.

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