F3 Physics URGENT!

1.(a) Drop in temperature = 8400/(4200x 0.1) 'C = 20'C

(b) Rise in temperature = 6300/(0.1 x 4200) 'C = 15'C
Hence, final temperature = (15+60)'C = 75'C

2. Let T be the final temperature, equating heat loss = heat gain
2c(T-10) = 3c(80-T)
where c is the specific heat capacity of milk
solve for T gives T = 52'C

3. Let T be the initial temperature of copper
Heat released by copper = 0.6 x 370 x (T - 30)
Hear absor by water = 1.2 x 4200 x (30-25) J = 25200 J
Hence, 0.6 x 370 x (T - 30) = 25200
solve for T gives T = 143.5'C

4. Let T be the final temperature
Hence, 0.05 x 4800 x (T-4) = 0.2 x 4200 x (80-T)
i.e. T = 63.1'C