This is the science of extremely small structures and is leading to advanced materials, devices and applications in energy, medicine and electronics that improve life, health care, safety and the environment.

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?

There are weak or strong attractive forces between atoms of liquids with a high viscosity

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative