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.

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)

Aspring has a relaxed length of 33 cm (0.33 m) and its spring stiffness is 6 n/m. you glue a 76 gram block (0.076 kg) to the top of the spring, and push the block down, compressing the spring so its total length is 15 cm. you make sure the block is at rest, then at time t=0 you quickly move your hand away. the block begins to move upward, because the upward force on the block by the spring is greater than the downward force on the block by the earth. calculate y vs. time for the block during a 0.09-second interval after you release the block, by applying the momentum principle in three steps each of 0.03-second duration.

Inside stars in space, the nuclei of hydrogen atoms fuse together to form helium atoms. this represents which form of energy? electrical energy nuclear energy chemical energy radiant energy