Suppose we want to use a hot brick at tbrick= 400 k to power an engine which is in contact with another thermal reservoir with tres=300 k. at what temperature of the brick will the engine stop doing work?

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.