$t=28.2s$

### Transcript for this Giancoli solution

Power equals the work done divided by the time it takes to do the work. And we can rearrange this formula to solve for it t and say that t equals the work done divided by the power output and we can figure out that the work is force times distance which is going to be the weight of this object times the height that its being raised divided by the power of the motor. That is the weight again ‘mg’x the height ‘h’ divided by the power and we’’ substitute the numbers, we have 315 kilogram’s in the sixth edition times 9.8 newtons per kilogram times 16 metres divided by the power of 1,750 wattsAnd this gives us the time of 28.2 seconds. And the fifth edition you change 315 to 285kg instead and the fifth edition answer is 25.5 seconds to raise the object.