How long does it take an immersion heater with a 500 W power rating to heat up 500 g of h2o from 15 c to 100 c if the water is in an aluminum cup with mass 200 g. the specific heat of aluminum is 99 j/ (kg K)

Answer 1

So you must heat 500 g H2O from 15 C to 100 C + 200 g Al dish from 15 C to 100 C.
q for H2O = 500 x 4.184 J/g x (100-15) = ? joules
q for Al dish = 200 x 0.099 J/g x (100-15) = ? joules
total q = qH2O + qAl = ? joules

The heater is 500 watts which is 500 Joule/second
500 J/s x # seconds = ? total J from above. Solve for seconds. Post your work if you get stuck.