An eager scientist on a hot summer day needs to determine how much ice to buy. She has a cooler which is filled with 36 cans of soda at a temperature of 82.9∘F. Each can has a mass of 375 g. The scientist wants the temperature of the drinks to be 40.1∘F. If there is no heat lost by the cooler and ignoring any heat lost to the soda containers, what mass ice of ice needs must she add to her cooler? Assume the temperature of the ice is 32.0 ∘F. The latent heat of fusion for ice is 80.0 cal/g, the specific heat of water is 1.00 cal/g·∘C, the specific heat of the soda is 0.900 cal/g·∘C, and there are 454 grams per pound.

Distance covered = speed x timethe distance traveled going against the stream = distance traveled with the stream.therefore it is the speed and the time that are the variables.as he travels the same distance both ways, speed x time is the same for each way.going upstream his speed is 4 kph; going downstream his speed is 6 kph.therefore we have two simultaneous equations: time upstream x 4 = time downstream x 6time upstream + time downstream = 60 minutestherefore we have the equation: time upstream = 6/10 hour, time downstream therefore = 4/10 hour.distance traveled at 4km/hr in 6/10 hour = 24/10 = 2.4km.check: distance traveled at 6km/hr in 4/10 hour = 24/10 = 2.4km.