Question

A crane lifts an I-beam up the side of a building. The crane's power output is 1750W for 20 seconds. After 20 seconds the I-beam was moving at 2 m/s and the mass has 200 kg. Use the work-energy process to determine the change in height of the I-beam.​

Answer 1

Step-by-step explanation:

This is one of those great problems that is harder to read than to solve!

Remember the following...

Power is the amount of work done over time.
`P = (W)/(t)`

and that work is Force times distance.
`W = F * d`

and that Force is just mass times acceleration.
`F = m * a`

So... nesting all the equations together we might get something that looks like.
`P = (m*a*d)/(t)`

We know the power, the time, the acceleration (at this given time) and the mass. We can then solve for d.
`d = (P*t)/(m*a)`

Plug and chug!