Question

A solid metal weighing 150g melts at its melting point 800°C by providing heat at the rate of 100W. The time taken for it to completely melt at the same temperature is 4min. What is the specific latent of fusion of the metal? ICSE 2018

Answer 1

Here is your solution:

rate of power =100W
time=4 minutes=4×60 sec=240 sec
heat provided in 240 sec for melting =240×100 =24000 J

weight of metal =150g
let L be the specific latent of fusion
then heat absorbed for melting = mL

so, mL=24000
or, 150L=24000
so, L=24000/150= 160 J/g

Thanks.

Answer 2

Answer:

energy =power*time

q=ml

Explanation:

energy=100W*4*60s:so as to covert to seconds

=24000J

24000J=0.15kg*L

ie;L=160000J/kg