General Knowledge - Physics - Discussion

I think the work done in both cases is the same. Because the potential energy is the same in both cases, because we deal with gravity and gravity is a conservative force.

Actually we know that perpendicular is the smallest distance,

So the normal force at a shorter distance will be more effective in lifting than a vector's of normal force in rolling.

The answer is definitly option D.

Same amount of work, just over a greater distance. It's gotta be C.

The answer is C. Work is force times distance. In this case, the force is the mass times gravity. Rolling up the hill reduces the magnitude of the force but increases the distance by the same magnitude, thus making the work the same; the rate is just decreased.

How is option B and D different?

When we lift the block,we have to work against the gravitational force Mg but to roll the block up on the inclined plane it requires less work as Mg gets resolved.

Force of gravity acting on stone in vertical position is greater than that of fprce acting during slidding position.

Let's consider the comments of both vivek & rajal here.

1) when the body is supposed to lift upwards the gravity acts on it in the opposite direction (downwards).

2) when its rolled on an inclined surface the acts frictional force. But the work done is more in lifting upwards this is because for our consideration let it be mass=1kg,then weight=9.8N(w=m*g)

Then you need a force greater than the weight.But when its to move inclined instead of vertical less force is needed.

Let us consider its inclined at an angle of 1o degree then the body exerts a vertical force of (9.8*sin10)N and horizontal force of (9.8*cos10)N .

Now compare the case 1 & case 2 this shows that a body can be moved in (horizontal & inclined) easily than vertically.

[Note :to get the horizontal & vertical components refer parallelogram law]

Thank you a lot for reading my comment.

Work done in rolling is less than lifting due to gravity.