Homework Statement
How much heat (in kcal) must be removed to make ice at –10°C from 2 kg of water at 20°C? (The specific heat of ice is 0.5 cal/g °C.)
Homework Equations
Q=cmT
The Attempt at a Solution
I thought this problem was simple,
Q=0.5x2000x30
Then diving by 1000 again...
I'm not entirely sure either. But using Q=cmT to find out the energy needed to heat the water, and then dividing by the intercepted energy.
Q=4x(1.08x10^26)x100
=4.32x10^26
Then divide by the intercepted power. Which converts to J/s.
The answer comes out wrong though.