7. How long does it take a 750-W coffeepot to bring to a boil 0.75 L of water initially at 8.0°C? Assume that the part of the pot which is heated with the water is made of 360 g of aluminum, and that no water boils away. )

Question

deoxna · Answer

Should I simply disregard the aluminium part? Because of not I have the problem that I don't know the initial temperature of the aluminium.

anonymous · Answer

find the joules (in heat) required to effect the change....

anonymous · Answer

water:
delta Q= V*rho*c*(92)

kettle:
delta Q = .36*c*(92)

anonymous · Answer

power = energy/time
t  = delta Q / (750 J/s)

deoxna · Answer

Ok, so then i should add the Q's? Also, do you just assume the kettle is at the same temperature as the water?

anonymous · Answer

yes and yes:)

anonymous · Answer

reasonable assumption, because if they weren't, then there'd be a problem to solve before we started solving the problem...

deoxna · Answer

Yeah thats what I thought. There are many questions on this worksheet, in that case, that require assuming temperatures to solve.... Anyway thanks alot.

anonymous · Answer

hope it helped.