7a. [4 marks] Cars I and B are on a straight race track. I is moving at a constant speed of and B is
initially at rest. As I passes B, B starts to move with an acceleration of.
I passes B
B passes !
1
> 45ms-
> 45ms-1
B
at rest, begins to move
B
At a later time B passes I. You may assume that both cars are point particles.
Show that the time taken for B to pass I is approximately 28 s.

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.

Is a copper wire a conductor or insulator?