The nucleus of any atom requires a strong force to hold it together. this strong force is required because a) the nucleus of any atom is so small. b) protons and neutrons repel each other. c) positive protons in the nucleus repel each other. d) the charges of the protons and the electrons cancel each other out.

Apiano tuner uses a tuner to create a tone of 5.00 x 10² hz. when a key on the piano is struck he hears 5 beats per second. what is a possible frequency of vibration for the piano string? 2500 hz 1300 hz 605 hz 495 hz

In a load, the load is paralel to the shaft. n a. angular n b. thrust n c radial n d. none of the above

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?