Use the following data:

cwater $=4190$ J$/$kgK$,$ cice $=2090$ J$/$kgK$,$ caluminium $=910$ J$/$kgK$.$

Lfusion $=3\mathrm{.}33$x$105$ J$/$kg$,$ Lvapourisation $=22\mathrm{.}6$x$105$ J$/$kg$.$

Q$4($a$)[6$ Marks$]$

Calculate the power needed to change $14$ g of ice at $-15$ oC to steam at $100$oC in $2$

minutes.

Q$4($b$)[6$ Marks$]$

A $50$ g aluminium disk at $300$ oC is placed into an insulated container with $158$ g water

at $10$ oC$.$ The aluminium is then quickly removed. The aluminium temperature is found

to have dropped to $120$ oC$.$ What is the new temperature of the water?