In a room of constant temperature A=20°C, a container with cooling constant k=0.1 is poured 1gallon of boiling water at T=100°C at time t=0. Waiting till t=10, I add 5 gallons of icey water Tice=0°C to the container, rapidly (ignoring pouring time). Compute the water temperature at t=15.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.

An owl dives toward the ground with a constant velocity of 4.40 m/s at 53.0° below the horizontal. the sun is directly overhead and casts a shadow of the owl directly below it. what is the speed (in m/s) of its shadow on level ground?