K.C.S.E Physics Q & A - MODEL 2013PP1QN15

K.C.S.E Physics Q & A - MODEL 2013PP1QN15

​(a) State the meaning of the term “specific latent heat of fusion”.
(b) Figure 8 shows a set up of apparatus used in an experiment to determine the specific latent heat of fusion of ice.

​The following readings were noted after the heater was switched on for 5 minutes:
- mass of beaker = 130 g
- mass of beaker + melted ice = 190 g
(i) Determine the:
(I) energy supplied by the 60 W heater in the 5 minutes. 
(II) specific latent heat of fusion of ice. 
(ii) It was observed that some of the crushed ice melted even before the heater was switched on. State a reason for this observation.

answers

 (a) Quantity of heat required to convert 1 kg of ice at 0 C to water without change in temperature;

​(iii) Heat from the surrounding melts the ice;