Question

A towboat pulls a ship with a horizontal force of 6.00⋅103N, moving the ship through the harbor 3.00km. If the boat does this in 15 min, how much power does the towboat use?

Answer 1

The towboat moves the ship by a distance

`d=3.00 km=3000 m`
so the work done by the towboat to move the ship is the product between the force applied and this distance:

`W=Fd=(6.0 \cdot 10^3 N)(3000 m)=1.8 \cdot 10^7 J`

The time taken for this process is

`t=15 min \cdot 60 s/min = 900 s`
So the power used by the twoboat is the ratio between the work done and the time taken

`P= (W)/(t)= (1.8 \cdot 10^7 J)/(900 s)=2.0 \cdot 10^4 W`