Question

How much time did it take Alex to move a stack of books if he did 1600 J of work and used 40 W of power?

Answer 1

40 seconds

Step-by-step explanation:

Power is defined as the rate of work done per unit time, expressed as
`P=\frac {W}{t}` where P represent power in Watts, W is work done in Joules and t is time taken. Making t the subject of the above formula then
`t=\frac {W}{P}` and substituting Work done, W with 1600 J while Power, P with 40 W then
`t=\frac {1600}{40}=40s`

Therefore, the time taken is equivalent to 40 s