OCR Physics A G484 Jan 2012 - The Newtonian World

What did people put down for the question that asked you to state two reasons why the temperature change may not be as high... it was that greenhouse question.

i put:
1. the greenhouse isnt perfectly sealed so some of the heated up air will escape and be replaced with outside air that is cooler, and
2. the air will transfer some of its thermal energy to the surroundings e.g. the glass..
no idea if thats the correct answer

Anybody else multiply the force by the frequency by 4 times the amplitude and get 4.32 W??

Please say somebody did as above :P

And i can't remember if it was 18mm or 1.8mm in the question about the speaker now, anybody remember that?

I think it was 1.8mm but i'm not sure...

For the acceleration question I got something around 0.41 and a few of my friends said they got a really high value, in the thousands. Could it be that they forgot to convert the amplitude to meters or am I just wrong?

i put:
1. the greenhouse isnt perfectly sealed so some of the heated up air will escape and be replaced with outside air that is cooler, and
2. the air will transfer some of its thermal energy to the surroundings e.g. the glass..
no idea if thats the correct answer

Did anyone notice on the Loudspeaker SHM question, it didn't specify the amplitude in the part it asked you to work out the Power. So i would say Any power should be allowed, I wrote this in my exam so we shall see what happens.

Oh, one of my mine points was the same as yours, the heat lost to surroundings, I also put that the soil may not be as efficient at transferring thermal energy to the air, I know it's stupid, but isn't valid do you think?

no if u think about it the acceleration should be really big, its going back and forth very quickly

Oh, one of my mine points was the same as yours, the heat lost to surroundings, I also put that the soil may not be as efficient at transferring thermal energy to the air, I know it's stupid, but isn't valid do you think?

I agree with this too, i got something that was like, 4.09 x 10^5 or something like that, it did look odd and i checked it and couldn't see where i might have gone wrong, then I thought 'hang on it is going backwards and forwards like, 5000 times a second'

Anybody else recognise the figure I've got above ^^?

other then heat losses, I wrote that, as the air gets hotter, so the temperature difference between the air and the soil would be reduced so less heat is transfered to the air, as thermal equillibrium is being established.....dunno if that is right though

Oh, one of my mine points was the same as yours, the heat lost to surroundings, I also put that the soil may not be as efficient at transferring thermal energy to the air, I know it's stupid, but isn't valid do you think?

I put about the heat being lost from the air to the surroundings, like the greenhouse walls, and I also said that the rate at which thermal energy is released by the soil, will diminish over the hour after the sun has gone down,

I'm quite confident with that, as I feel that's why they involved the phrase '12W immediately after sunset' in the question

it asked for the power required to provide the average force.. not sure what ur talking about

I put about the heat being lost from the air to the surroundings, like the greenhouse walls, and I also said that the rate at which thermal energy is released by the soil, will diminish over the hour after the sun has gone down,
I'm quite confident with that, as I feel that's why they involved the phrase '12W immediately after sunset' in the question

For the answer asking for the satellite that has 24 hours, what was the answer?

Isnt that geostationary satellites

Yes but do you know what the question ask exactly?

Did it ask for the type of satellite? or...