A30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. the wavelength of the constituent traveling waves is:

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

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?

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?