This section contains numerical assignments, points to ponder, numerical examples and other brain teasers in Thermodynamics, Grade 11.

Assignment 1

An ideal gas absorbs 5.00 × 10^{3} J of energy while doing 2.00 × 10^{3} J of work on the environment during a constant pressure process. (a) Compute the change in the internal energy of gas. (b) If the internal energy now drops by 4.50 × 10^{3} J and 7.50 × 10^{3} J is expelled from the system, find the change in volume, assuming a constant pressure process at 1.01 × 10^{5} Pa.

During one cycle, an engine extracts 2.00 × 10^{3} J of energy from the hot reservoir and transfers 1.5 × 10^{3} J to a cold reservoir. (a) Find the thermal efficiency of the engine. (b) How much work this engine do in one cycle? (c) What average power does this engine generates if it goes through four cycles in 2.50 s?

Find the change in the entropy of 3.00 × 10^{2} g of lead when it melts at 327° C. Lead has a latent heat of fusion of 2.45 × 10^{4} J/kg. (b) Suppose the same amount of energy is used to melt part of a piece of silver which is already at its melting point of 961° C. Find change in the entropy of the silver?