OCR 21st Century Science Physics P4 P5 P6 *Unofficial Mark Scheme 2016*

The question asked why isn't the two forces an interaction pair. And the original statement said interaction pairs like don't act on different objects hence why I thought the answer would have been different So just restating what an interaction pair isn't won't gain marks alone.

I and most of my friends agreed with your original answer. The question asked why is he wrong, and most of us said he didn't mention the fact that interaction pairs act on different objects. There isn't any need for movement for something to interact either

The question asked why isn't the two forces an interaction pair. And the original statement said interaction pairs like don't act on different objects hence why I thought the answer would have been different So just restating what an interaction pair isn't won't gain marks alone.

Oh my answer didnt actually say what an interaction pair isn't, but I doubt it was right. What was the actual answer if you know?

There's a lot of answers for this question and in my opinion this was a poor, ambiguous question. I would have mentioned the fact the car was stationary and the forces had no overall effect. But, in textbooks and revision guides, scenarios like these have been said to be interaction pairs so I'm confused. Sometimes I feel there was an error in the question but in general, I felt it was a vague/poor question.

According to bitesize, the forces aren't an interaction pair because the weight of the lorry is caused by the Earth's gravity, not by the road. Therefore the forces aren't between 2 objects, rather 2 objects and gravity. (Weight=lorry and gravity, reaction=road and gravity).

I'm not sure how ou would phrase that though.

I just sat in the hall thinking that he actually was right. What a stupid question.

Ahh I get it. It was quite stupid to be honest, as we were taught that it was an interaction pair before

Thanks for making this! Hopefully I can get that rare A* in Physics and am confident about it now after reading this! Great!

I reckon I got around 50 marks in this paper. Do you think that'll be enough to merit 100UMS?

Yeahh -- should be enough. Generally, was it a harder paper than previous years I'm not too sure. Maybe 43-ish for the A* so 50 marks could very much be 100UMS!

According to bitesize, the forces aren't an interaction pair because the weight of the lorry is caused by the Earth's gravity, not by the road. Therefore the forces aren't between 2 objects, rather 2 objects and gravity. (Weight=lorry and gravity, reaction=road and lorry).

I'm not sure how ou would phrase that though.

I just sat in the hall thinking that he actually was right. What a stupid question.

Ahh I get it. It was quite stupid to be honest, as we were taught that it was an interaction pair before

I knew he wasn't right, but I didn't know why he wasn't right.
I agree, it was a stupid, vague question

I picked Source B instead of C -- will this majorly affect my marks for the [3] question??

Worst thing is the textbook states gravity is an action at a distance interaction pair but it's fine

I think you'll get one mark for talking about half life.
I think it was one mark for correct source, one mark for correct type of radiation, and one mark for talking about half life.

I ruled-out A and B straight away (because they were both alpha, and so couldn't leave the body); I then discussed half-life, but ended-up choosing source D. Should this still score 2/3 marks? (As I got the wrong source!)

What was the half life like for source D? I didn't even look at it

Way too low, something like 1000 start and 75 after the first hour.

After looking at this im sure i've actually done really well on the exam par a couple of questions, like the awful interaction pair. I also messed up my parallel curcuit calculations, but for some reason i always do that haha, they were only 1 markers anyway so no worries. Everything else though on here seems to roughly match mine however

Ah yeah, I think you'll only get a mark then.
From that I assume you can only get 1 mark max if you didn't pick source C!! Bit harsh really