How much work is done in displacing a tall box for 15 m with a force equal to 400 N, when it is applied slightly upward at an angle of 10.0° from horizontal? (W = F. d. cos 6).
10°
2
o 6000 Joules
. 6900 Joules
5908.8 Joules
04980.9 Joules

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?

What is the most useful equation for electric power?

14. a body is projected with velocity vi from a.at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is