Amass on a spring is observed to complete 15 oscillations in 30 seconds. what are the period and the frequency of motion?

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?

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c

Which property is expressed in distance units? o a. period o b. wavelength o c. speed o d. frequency