- #1
physicsnerd7
- 12
- 0
Homework Statement
Determine the amount of time it will take a 1000 W electric kettle to heat up 1.0 L of water to boiling point if the water starts at 10 °C and the kettle is made from 400 g of iron. The transfer of heat energy from the kettle to the water is 63%.
Homework Equations
P = W/Δt
Q = mcΔT
The Attempt at a Solution
Okay so what i was thinking was find 63% of the 1000 W electric kettle and then that is the power used to bring the water to a boil so I did -
Pfor water = 1000W x 0.63
= 630 W
then I would use this power in the formula P = W/Δt to find time so I did -
Δt = (mwater x cwater x (Tf of water - Ti of water) ) / 630 W
= (1kg x 4.2E3 J/kgC x (100 C - 10 C )) / 630 W
= 600s ||or|| 10 min
apparently this answer is wrong because I am suppose to incorporate the mass of the iron kettle but I don't know how. Please help!