Question

The force needed to push a load up an inclined plane is less than the force needed to lift it directly.give a reason

Answer 1

Let's consider two different cases here.

Case 1: When the load is lifted directly to a height H.

In this case, let the required force be F. So, the work done is FH (Force X Displacement) .

Case 2: When the load is pushed up an inclined plane to a height H.

In this case, the displacement of the load will be more than H, let's say the displacement is H1. Also, let's say the force required in this case is F1. So, the work done is F1H1.

Since, the final height of the load is the same in both cases, work done will also be the same (work done = Change in potential energy, which is the same in both cases).

This means that

FH = F1H1

Since H1 > H, from the above equation we can say that F1 < F.

HOPE IT HELPED YOU !!!! ALL THE BEST

Answer 2

because in an inclined plane we work against two forces friction and gravity but in case of lifting we work against gravity.