Two synchronized microwave sources, a and b, are emitting waves of wavelength 4.0 cm. source a is located on the x-axis at x = 0, source b can be moved along the x-axis, and a microwave receiver is fixed on the x-axis at x = 99 cm.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

It is really hard for me right know

The discovery of the electron as a subatomic particle was a result of