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Unit 5 Physics Edexcel A2 and Edexcel IAL

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Original post by tangotangopapa2
A general question: Do you loose mark for giving your answers to greater significant figures than required?


Generally, yes, it's always up to 1 sig fig greater than the numbers they provide.
Original post by tangotangopapa2
A general question: Do you loose mark for giving your answers to greater significant figures than required?


Unless the SF requirement is specfically stated in the question, then no.
Please can someone explain why the answer to question 2 isn't D.

https://a4942901ab27cf2817f7a4f7497d95e45091f796.googledrive.com/host/0B1ZiqBksUHNYTU9SWFFTVjI5T0k/January%202015%20(IAL)%20QP%20-%20Unit%205%20Edexcel%20Physics.pdf
(edited 7 years ago)
Original post by Connorbwfc


the answer is B?
Original post by SuruthiG
the answer is B?


Sorry, I mean't why isn't the answer D?
(edited 7 years ago)
Original post by Connorbwfc
Sorry, I mean't why is the answer D?


As the block gets hotter relative to its surroundings it radiates heat to the air.
Original post by 16characterlimit
As the block gets hotter relative to its surroundings it radiates heat to the air.


Exactly.

Why is overestimating the mass of the block a more likely occurence that this?

Ignore me i've realised why I am wrong.
Would my answer lead to them getting a value greater than the textbook value?
(edited 7 years ago)
Original post by Connorbwfc
Exactly.

Why is overestimating the mass of the block a more likely occurence that this?

Ignore me i've realised why I am wrong.
Would my answer lead to them getting a value greater than the textbook value?


Overestimated mass would mean a lower heat capacity, since Q/mDt = c, higher m means lower c.
(edited 7 years ago)
Original post by 16characterlimit
Overestimated mass would mean a lower heat capacity, since Q/mDt = c, higher m means higher c.


Wouldn't a higher m give you a smaller c according to your equation?
Original post by demotivated
Wouldn't a higher m give you a smaller c according to your equation?


sorry, I thought that, I wanted to write that but it didnt come out
Hey everyone...would appreciate if anyone would help me in this question:

Olympus Mons is the highest mountain on Mars. The height of Olympus Monsis 22 km, which is 0.6% of the radius of Mars.The change in gravitational field strength from the bottom to the top of Olympus Mons is
A – 0.6%
B – 1.2%
C + 1.2%
D + 0.6%
Energy is supplied to a fixed mass of gas in a container and the mean squared speed ofthe gas molecules doubles.The absolute temperature of the gas
A remains constant
B increases by a factor of 2
C increases by a factor of square root 2
D increases by a factor of 4

The correct answer is C but why?
Minus 1.2%
Original post by Rahatara Sadique
Hey everyone...would appreciate if anyone would help me in this question:

Olympus Mons is the highest mountain on Mars. The height of Olympus Monsis 22 km, which is 0.6% of the radius of Mars.The change in gravitational field strength from the bottom to the top of Olympus Mons is
A – 0.6%
B – 1.2%
C + 1.2%
D + 0.6%



F=GM/r^2.

Let r^2 for Mars=1
so r^2 for Mountain=1.006.

Sub in these numbers and you get the answer (obviously a negative as it decreases)
Original post by Rahatara Sadique
Energy is supplied to a fixed mass of gas in a container and the mean squared speed ofthe gas molecules doubles.The absolute temperature of the gas
A remains constant
B increases by a factor of 2
C increases by a factor of square root 2
D increases by a factor of 4

The correct answer is C but why?


Are you sure the answer is C?

I would've expected B due to 0.5m<c^2>=1.5kT.
Original post by demotivated
Unless it was a ratio of energies, then they would give you the spring constant as well.


Ok thanks - so k is the spring constant?
Original post by Connorbwfc
Are you sure the answer is C?

I would've expected B due to 0.5m<c^2>=1.5kT.


The answer is B, I did this question earlier today.
Screen Shot 2016-06-27 at 10.53.20 PM.pngcan someone explain this to me please?
Original post by Ppatel0
Minus 1.2%


Can you please explain why that's the answer? Thankyou :smile:
Original post by Connorbwfc
Are you sure the answer is C?

I would've expected B due to 0.5m<c^2>=1.5kT.


Yes, I have checked the marking scheme again and it says C.
But mean square speed is proportional to temperature...

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