GCSE OCR 21st Century Triple Science (CBP1-7) Thread

OP

Original post by olmyster911

I kinda put tracers :frown:

How many marks will I lose if I put food, tracers & cancer?

Posted from TSR Mobile

It was worth two marks, so only 1.

Original post by olmyster911

Any confirmation of it being average?

Posted from TSR Mobile

Original post by olmyster911

"Instantaneous speed is an average over a really short period of time"

Would 9.7 seconds be enough to be considered instantaneous?

Posted from TSR Mobile

I can't confirm anything sadly, but to be honest it kind of seems alright when reading that. The thing is, it depended on that equation - I've never seen 'average velocity' only 'instantaneous velocity' hence why I put it.

Original post by cupcakes16

I put 9 so would I get the mark for that?

They'd accept a range, since the graph ended in the third mini box (9.7) on the graph they'd probably accept +- 0.1 (or at least in maths) so probably not, unless you stated rounded to nearest whole number/drew a line to confirm 9 I think.

(edited 9 years ago)

Reply 1583

Was there a 3 in front of one of the elements in the decay question? :eek:

Reply 1584

OP

Original post by Magnesium

Was there a 3 in front of one of the elements in the decay question? :eek:

On the right hand side, it looked like this:

3n⁰ and a 1 underneath the 0 or was it a 1 and a 0 underneath? Something like that, but yes there was a 3 there.

(edited 9 years ago)

Reply 1585

Original post by Sulfur

These are what I put, can anyone give an approximate mark (or correct them! :rolleyes:

)

P4 6 maker:

At the start all of the forces are stationary (weight and gravity are constants)
When he runs, he begins to accelerate and build up momentum
Air resistance is not a greater force after a bit, his resultant force is to go forward (driving force) from the build up of forces
When continuing to run, he builds up more acceleration and momentum (work done)
This results in a greater K.E and when he jumps he transfers the energy to go higher/further
KE = work done, KE turns to GPE and then he begins to fall

P5:

Filament lamp wire is smaller so there are more collisions with the free moving ions
This results in a greater resistance and the temperature rises
This causes the filament lamp to glow
Connecting wires are bigger so there are less collisions with the free moving ions
This results in less resistance and the temperature isn't as great
This means that the wires don't glow
I think I put something else too (anyone got an idea? :tongue:

), but my answer filled the last line only.

P6:

I agree that there are risks as radioactive waste emits ionising radiation
Ionising radiation can kill/damage cells and cause mutations and cancer if people are close to the power station
However, power stations are built away from most people and disposed of correctly
Low level waste - (e.g medical gloves? :confused:

) - disposed on dumps/landfill sites - has a long half life, low activity - but public could still be affected
Intermediate level waste (e.g surgical equipment? :confused:

) - disposed of by putting it in cement and steel contains - shorter half life, more activity - away from public as it's underground
High level waste (forgot to put an example...) - short half life, high activity - put in glass (vitrification), cooled to reduce heat and put underground in containers - away from people
Overall, there are risks but the benefits (no CO2, more energy) outweighs the risks of radioactive waste.

In the filament lamp, the filament wire has a high resistance therefore when electrons pass through it, it causes the positive stationary ions inside it to vibrate leading to an increased level of kinetic energy and heat - this causes it to glow. The filament wire is also made of metal and therefore is a conductor with free charges to move so the electrons can transfer energy to it and make it glow. The wires itself have a very low resistance, so low that it is normally ignored and therefore the electrons would not make it vibrate as much as something with high resistance. The wiring is also surrounded by plastic which is an insulator and has few free charges to move and therefore doesn't conduct electricity. This means that it will not glow when the charge passes through it :smile:

(Or atleast that's what i put :tongue:

)

Reply 1586

OP

Original post by Magnesium

In the filament lamp, the filament wire has a high resistance therefore when electrons pass through it, it causes the positive stationary ions inside it to vibrate leading to an increased level of kinetic energy and heat - this causes it to glow. The filament wire is also made of metal and therefore is a conductor with free charges to move so the electrons can transfer energy to it and make it glow. The wires itself have a very low resistance, so low that it is normally ignored and therefore the electrons would not make it vibrate as much as something with high resistance. The wiring is also surrounded by plastic which is an insulator and has few free charges to move and therefore doesn't conduct electricity. This means that it will not glow when the charge passes through it :smile:

(Or atleast that's what i put :tongue:

)

Ah sugar yes! I forgot about the conductor/insulator part but to be honest I probably wouldn't have thought of it in the exam. I was wondering whether or not to mention the little resistance in wires so they're usually ignored though.

Reply 1587

username1344042

Original post by Sulfur

It was worth two marks, so only 1.

I can't confirm anything sadly, but to be honest it kind of seems alright when reading that. The thing is, it depended on that equation - I've never seen 'average velocity' only 'instantaneous velocity' hence why I put it.

That's why I put it also! I'd only heard of instantaneous speed and my physics teacher specifically referred to it as that so I put it.

Posted from TSR Mobile

Reply 1588

Original post by Sulfur

On the right hand side, it looked like this:

3n⁰ and a 1 underneath the 0 or was it a 1 and a 0 underneath? Something like that, but yes there was a 3 there.

oops completely forgot to look at the 3. oh well, it was like 2 marks right?

Reply 1589

OP

Original post by Magnesium

oops completely forgot to look at the 3. oh well, it was like 2 marks right?

Yup - in a previous exam paper they award marks for:

Getting the bottom part of the equation right (1)
Getting the top part of the equation right (1)

So along as you got 40 I think it was on the bottom (Te) then you'd get 1 mark.

Reply 1590

Original post by Sulfur

Yup - in a previous exam paper they award marks for:

Getting the bottom part of the equation right (1)
Getting the top part of the equation right (1)

So along as you got 40 I think it was on the bottom (Te) then you'd get 1 mark.

Ah oh well, the rest of the paper went well so I guess it's okay :tongue:

Reply 1591

Original post by olmyster911

Any confirmation of it being average?

Posted from TSR Mobile

Yeah I got average and most people got average in my school

Reply 1592

Original post by brodingoson

Last year it was 38 for an A*

Posted from TSR Mobile

Um it was defo 34 for an A* in p456. Look at the ocr website.

Reply 1593

Original post by nelizabeth_

I did...
- cancer
- sterilises equipment

Can't remember the third one I ticked

I did that too, I think the last one was food too (killing bacteria)

Reply 1594

Exa

How many marks do you reckon I would get on the filament question cause I put thicker wire would have more resistance :/ but I explained the collision theory and stuff right? I am so annoyed. It was such an easy question :L

Reply 1595

OP

The boundaries for P456 (A*) have been:

June 2012 - 39
January 2013 - 33
June 2013 - 34

What does everyone think they'd be this year?

Reply 1596

Krollo

Original post by Sulfur

The boundaries for P456 (A*) have been:

June 2012 - 39
January 2013 - 33
June 2013 - 34

What does everyone think they'd be this year?

I think it was a fair bit easier than last year, but not too easy. I'll go 36-37 for an A*.

Reply 1597