The power may be exerted behind the weight, as in [Fig. 58].

Fig. 58.

Will any more power be needed behind the weight than before it?

No; the power required is the same in both cases.

Would it require as much power to roll barrels into a wagon as to lift them in?

No; they can be rolled into a wagon much more easily than lifted in.

Can they be taken out of the wagon any more easily on an inclined plane than without one?

Yes; they can be taken out more easily on an inclined plane.

Why are drays, used in cities, made in the form of the inclined plane?