Question

How long would it take a 1000W heater to melt 1.00kg of ice at -20.0°C, assuming all the energy from the heater is absorbed by the ice? (a) 4.18 s(b) 41.8 s (c) 5.55 min (d) 6.25min(e) 38.4min

Answer 1

Heat for -20 to zero = .48 * 1000 = 480 calories

Heat to melt ice = 1000 * 79.7 = 79700 calories

Total calories required = 80,200 calories

80,200 cal * 4.19 J/cal = 336,000 J

336000 J / 1000 J/sec = 336 sec

336 sec / 60 sec/min = 5.6 min

(c - 5.55 min)