General Knowledge - Physics - Discussion

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

Like pulling is easier than pushing. Concept of friction.

Work done in rolling case also include frictional coifficient of both the surface which reduce word done as compair to lifting.

Work done in rolling is less than lifting due to a extra work has been done in lifting due to gravity means against the gravity but in rolling on a inclined plane we get a work done by gravity in downward direction along the gravity.

The answer will be fall on the option if we look the question thoroughly.

In rolling there's two components horizontal and vertical are acting and so the force or work required to roll on slope is divided into frictional resistance and partially to gravity. While in case of lifting have to overcome only the vertical component i.e, gravity so it becomes hard to fight gravity than to friction.

Answer is D during rolling on an inclined plane the sin (downward) component of gravitation force is zero while cos component is present at the time there is pushing force which is greater and opposite to this component of force and hence this component of force is neglected. And there is only force that is pushing force.

Hence work done is less in rolling.

During rolling a stone potential energy stored in the body and kinetic friction between the stone increases and during lifting the body, the work done against the gravity according to newton second law. F=ma. During rolling the stone the force is towards the earth and also momentum increases.

The correct answer is C. The work done in lifting is just the increase in potential energy, whereas the work done on the incline plane is the sum of the increase in potential energy and the work done against friction. Thus the work done along the inclined plane is in fact greater.

The answer should be "C". The total work done is how much distance the stone was moved from it's initial position. When you lift you the stone up and bring it down to the final destination the total distance is same and so the work done is same. The time it takes you to roll it is generally longer than lifting it. So the work done is same but the rate of work done is different. You use more "power" in lifting it but same "energy" as rolling it up. So more power is used for lifting it than rolling it but same work (energy) is used.