Work, Energy & Power: Solving 20 & 21 Problems

[McKeavey]

Homework Statement

20. How much work can a 22kW car engine do in 60s if it is 100% efficient?

21. A force of 5.0N moves a 6.0 kg object along a rough floor at a constant speed of 2.5m/s.
a) How much work is done in 25s?
b) What power is being used?
c) What force of friction is acting on the object?

Homework Equations

The Attempt at a Solution

I would guess that I need to use W = F * d , but got nowhere.

W = F * d
P = E/t
got nowhere too..

 

[issacnewton]

Work= Power x time. so much work would the car do, since P =22 kW and t=60 s ?

since its 100 % efficient, all the energy given by the engine is used for moving the car