Determine the frequency of the a. third harmonic for a string whose first harmonic
frequency is 150 Hz.
b. fourth overtone for a string whose fifth harmonic frequency
is 1500 Hz.
c. First harmonic for a string whose third harmonic
frequency is 850 Hz.

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?

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

Aperson standing in a canoe exerts a force of 700 n to throw an anchor over the side. find the acceleration of the canoe if the total mass of the canoe and the person is 100 kg?