Question

Q 11:

One container holds 0.10 kg of water at 75 ∘C and is warmed to 95 ∘C by heating from contact with the other container. The other container, also holding 0.10 kg of water, cools from 35 ∘C to 15 ∘C. Specific heat of water is 4180 J/kg⋅∘C.

Part A:

Estimate the total change in entropy of two containers of water using the actual temperatures to determine the heat transferred to each container and the average temperatures to determine the change in entropy.

Express your answer with the appropriate units.

Part B:

Is this energy transfer process allowed by the first law of thermodynamics? Yes or No

Part C:

is this energy transfer process allowed by the second law of thermodynamics? Yes or No

Q 12:

A house at 19 ∘C transfers 1.0×105J of thermal energy to the outside air, which has a temperature of -10 ∘C.

Part A:

Determine the entropy change of the house-outside air system.

Express your answer with the appropriate units.

Q 13:

A 62-kg woman walking on level ground at 1 m/s metabolizes energy at a rate of 210 W . When she walks up a 5.0∘ incline at the same speed, her metabolic rate increases to 360 W .

Part A:

Determine her efficiency at converting chemical energy into gravitational potential energy. Do not include in the input energy the energy consumed by the women when she walks on level ground.

Answer 1