Power questions

PFY, p. 120

f) Power is the rate of doing work.

Power (in watt) = work done (in joule)/ time (in seconds) 

g) 1 Watt is a rate of working of one joule per second.

13. P = E/t

P = 1000/5

P = 200 W

14. Wd = F x d

Wd = 300 x 2

Wd = 600 J

P = Wd/t

P = 600/ 3

P = 100 W

15. Wd = F x d

Wd = 3000 x 10

Wd = 30,000 J

P = Wd/t

P = 30,000/ 4

P = 7500 W or 7.5 kW