Physics HELP!

[Adahshan]

http://www.xtremepapers.me/CIE/Cambridg ... 5_qp_1.pdf

Q 14 AND 15 I can't get to understand. 15 yes but still i keep asking myself why why why to everything i try to say.

Also, there is a question in paper 1 with 4 boxes and a question about who has the greatest thermal capacity? What is meant by that?

Can someone explain both in detail?

 

[mrstealyourgirl]

See in question number 14 they are asking the movement of the pollen grains .... Always remember these type of questions relate to brownian motion as in the zig zag movement of particles in random direction ...... Qno 15 is telling u that the piece of spark is actually a very hot piece of small metal but then the twist is that the observer doesn't feel any heat ..... This specifically means that the piece of metal (spark) has a high thermal capacity........... Now high thermal capacity doesn't mean it has more internal energy, it means that it gains heat quickly and loses it very quickly ! Hope it helped buddy

 

[haochen]

mrstealyourgirl ur explanation about the thermal capacity is wrong eventually the opposite
if some object have high thermal capacity it will take more heat energy to raise 1'C of its temp.
while if some object have low thermal capacity it will take the same heat but the temp will raise more than the previous one and losses the energy fast
so Q15 the metal have low thermal capacity because it gain heat and burn but it loss energy fast so the welder cant feel it.

and about the box question it is here http://www.xtremepapers.me/CIE/Cambridg ... 3_qp_1.pdf
and they asked u which box have the highest thermal capacity. which is the one with lower temp because temp of object will raise less

hope that help
and gud luck in ur exam