Earth receives 1400 `W//m^(2)` of solar power. If all the solar energy falling on a lens of area `0.2m^(2)` is focussed onto a block of ice of mass 2.80g, it takes 110t(in sec) time to melt the ice. Value of t is:

Explanation

Heat received per second
`=(1400)(0.2)=280J`
Required heat for meting of the block=(0.28)
`(3.3xx10^(5))=9.24xx10^(4)J`
Required time `(9.24xx10^(4))/(280xx60)=5.5` minutes.