An office worker uses an immersion heater to warm 250 g of water in a light, covered, insulated cup from 20°c to 100°c in 4.00 minutes. the heater is a nichrome resistance wire connected to a 120-v power supply. assume the wire is at 100°c throughout the 4.00-min time interval. specify a diameter and a length the wire can have. can it be made from less than 0.5 cm3 of nichrome?