1) A motor does 600 J of work in 3 s. What is the power output? a) 150 W b) 200 W c)  300 W d) 400 W 2) If a machine produces 500 W for 10 s, how much work is done? a) 5 J b) 50 J c)  5000 J d) 50000 J 3) Which of the following is the SI unit of power? a) Joule-second (J·s) b) Newton (N) c) Joule per meter (J/m) d) Watt (W) 4) A person lifts a 200 N box to a height of 2 m in 4.0 s. What is the power? a) 150 W b) 100 W c)  80 W d) 50 W 5) If the power of a pump is doubled while doing the same amount of work, what happens to the time taken? a) Doubled b) Halved c) Remains the same d) Reduced to one-quarter 6) Rearrange the formula P = W/t to find t. a) t = P/W b) t = W/P c) t = W.P d) t = 1/W.P 7) Which expression correctly shows power in terms of force F, distance d, and time t? a) F.d/t b) F.d.t c) t/F.d d) F/d.t 8) Which quantity must be known in addition to power to calculate work done? a) Force b) Mass c) Time d) Distance 9) Which relationship is correct if power is constant? a) Time is proportional to work done. b) Time is inversely proportional to work done. c) Time is proportional to power. d) Time is inversely proportional to power. 10) A car engine produces 75 kW of power. If it works for 1 hour, what is the total work done in joules? a) 75 J b) 7500 J c) 2.7 x 106 J d) 2.7 x 108 J

Demonstrate calculation of power using the appropriate formula

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