Aqa as physics 2018 unofficial mark scheme

Original post by Matt Barnes

i also said this, i also said how the added mass would not decrease velocity since there was no friction/resistive force, therefore the added mass woud have no effect on the velocity.

That's what I was thinking.

Reply 22

Matt Barnes

1

Original post by kishxx01

No but momentum must always be conserved so velocity has to decrease.

yeh, youre right. however if velocity decreased it would counter the rise in momentum so the answer would be contradicted? im not sure but would momentu be conserved in this scenario with the frictionless floor, potentially the air resistence may still conserve momentum by decreasing velocity due to newtons third law??

Reply 23

Matt Barnes

1

Original post by Matt Barnes

yeh, youre right. however if velocity decreased it would counter the rise in momentum so the answer would be contradicted? im not sure but would momentu be conserved in this scenario with the frictionless floor, potentially the air resistence may still conserve momentum by decreasing velocity due to newtons third law??

i think you are correct, my bad

Reply 24

NaomiWilso

6

How many marks do you think you will have to get in each paper to get a B?

Reply 25

Original post by NaomiWilso

How many marks do you think you will have to get in each paper to get a B?

82/140 if we calculate the average from previous papers.

85/140 if you want to gaurantee.

Reply 26

OP

Original post by randint

82/140 if we calculate the average from previous papers.

85/140 if you want to gaurantee.

I hope Its low. I need an A and I got like 40/70 in paper 1

Reply 27

OP

Original post by MissFattyFatty

PLEASE CHECK OUT MY QUESTION ABOUT STRICT PARENTS AND BRAS AND GOING OUT -----I POSTED IT MONTHS AGO AND NO-ONE REPLIED------- IM NEW TO THIS

https://www.thestudentroom.co.uk/showthread.php?t=5251710#primary_content

You are aware this is a PHYSICS thread?

Reply 28

OP

Original post by randint

82/140 if we calculate the average from previous papers.

85/140 if you want to gaurantee.

WHAT??? I would expect this to be the boundary for the grade A not B

Reply 29

Original post by kishxx01

WHAT??? I would expect this to be the boundary for the grade A not B

It's roughly 50% for a b. As much as I would love the grade boundaries to be incredibly low, you have to think realistically here.

Reply 30

OP

Original post by randint

It's roughly 50% for a b. As much as I would love the grade boundaries to be incredibly low, you have to think realistically here.

Last yr was 83/140 for A

Reply 31

Original post by kishxx01

Last yr was 83/140 for A

i looked at the wrong grade boundaries.

around (70 to 75)/140 for a b.

(edited 5 years ago)

Reply 32

NaomiWilso

6

Original post by kishxx01

I hope Its low. I need an A and I got like 40/70 in paper 1

Are you carrying on physics to year 2?

Reply 33

OP

Original post by randint

i looked at the wrong grade boundaries.

around (70 to 75)/140 for a b.

And I would say last yrs paper was easier than this yrs paper 1 so it should be around 80/140 for A

Reply 34

OP

Original post by NaomiWilso

Are you carrying on physics to year 2?

No

Reply 35

Electravess

4

I'm also dropping physics - or, well, have dropped it now. I ended up with values of 7500N and 10000N for 4.4 to 2.s.f., and my friend got the same.
Considering the weight of the beam was 12000N and was balanced evenly, I assumed that the vertical component of tension in each cable was 6000N, then using this value with SOH CAH TOA and the angles to resolve in the direction of tension.

Picture shows this (I wasn't sure which side was which angle but these are the two solutions I had)

(edited 5 years ago)

Reply 36

Digital_King321