Turn on thread page Beta
 You are Here: Home >< Physics

# Official OCR A2 G484 June 2016 [Module 1] [90UMS] watch

1. (Original post by AlexeiLipov)
For sketching graph I got this
**** sake. I had KEmax as 80mj. So that means my second part of the answer is wrong too. How many marks would I lose for that?
2. (Original post by rm761)
lol same, seems impossible tho
Our galaxy weighs ~1x10^43, so that would be a VERY heavy star :P
3. (Original post by Zonothene)
As its a binary system you have to use this if you wish to do it using kepler's 3rd law (i.e adding the two masses together in the equation).
So I'm ****ed.
Great. Goodbye 100% ums. ****ing ********
4. (Original post by victoria98)
Screwed up the KE graph..., thought the maximum was 80mJ. Such a silly error... It was two marks though, what would the other mark be for? Also will there be ecf for maximum speed with 80mJ, or will they only give ecf for the time period?
So the max was 50mj right?
5. (Original post by Pyslocke)
**** sake. I had KEmax as 80mj. So that means my second part of the answer is wrong too. How many marks would I lose for that?
I can't remember how many marks the graph sketching was, I think 1 mark. So you only lost 1 mark because the other parts of the question you will get error carried forward.
6. (Original post by rm761)
lol same, seems impossible tho
It's a star. The sun is 1x10^30. Binary stars are usually massive.
7. (Original post by Asiimov)
I think most are saying 5/4pi, I think you might have miscounted
i got 5/8PI as the phase difference, would 5/4PI mean its out of phase by 1/4PI???
8. Okay, so for the question about Mars' moons. What did everyone write for the speed of the moon? It said EXPECT to see so I said you would expect it to decrease in speed because the mean gravitational field acting on the moon decreases? Assuming their masses affect each other. But seriously... wtf
9. For S2 mass could i do this:

F = GM1M2/r1^2 = M1v1^2/r1 which M1 cancels
GM2/r1^2 = v1^2/r1
Rearrange for M2.

I'm not sure what answer i got but is that a correct method?
10. DIFFICULTY POLL:
http://www.thestudentroom.co.uk/show....php?t=4176590

votevotevote
11. (Original post by President J)
It's a star. The sun is 1x10^30. Binary stars are usually massive.
thats why i didnt think the 41 was too weird, i thought s2 must be so big that s1 revolves around it like the earth does around the sun fgs, then i googled mass of largest star ffs
12. same
13. I got 10^33 as the mass of star 2. Is this right?
14. (Original post by Smeagul)
I got 10^33 as the mass of star 2. Is this right?
that is the correct power yes
15. There goes my A

Go to hell G484.
16. for the fireman question, i did 92g - 8.3gsin55 :/ is this correct?
17. (Original post by neyjunior)
for the fireman question, i did 92g - 8.3gsin55 :/ is this correct?
Had to be plus. Hose would push you back.
18. (Original post by neyjunior)
for the fireman question, i did 92g - 8.3gsin55 :/ is this correct?
No, the vertical component of the contact force is equal to the weight of the fireman plus the vertical component of the impulse of the water. Answer = 92g + 8.25*(whatever the speed of the water was)*sin(55)
19. (Original post by President J)
Had to be plus. Hose would push you back.
how many marks do you think i'll lose for that?
20. (Original post by Zonothene)
No, the vertical component of the contact force is equal to the weight of the fireman plus the vertical component of the impulse of the water. Answer = 92g + 8.25*(whatever the speed of the water was)*sin(55)
how many marks do you think i'll lose?

Reply
Submit reply
Turn on thread page Beta

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: August 23, 2016
Today on TSR

### Exam Jam 2018

Join thousands of students this half term

Poll
Useful resources

## Make your revision easier

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.