General Knowledge - Physics - Discussion

When we are lifting any object vertically, we just work against gravity (non-contact force). It is no matter whether the road is slope down or slope up. But in 2nd case, the concept of frictional force (contact force) is introduced. A roller touches its minimum parts on ground, so there less friction arises and it is easy to move. In case of moving downward we have to apply less energy than to moving upward just because of gravity.

When a stone is rolled up in an inclined plane than it is easier to apply force in upward direction because pulling is easier than pushing & one can use it's own weight while pushing as in case of pulley. So the answer will be D because firstly gravity is acting directly & vertically downward and secondly frictional force is introduced less in an inclined plane due to minimum contact with the road.

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

We know that a slope has a angle and a friction cause for non plane surface though gravity force F=mg where g is approxi constant so the force depend on the mass of object when we pull that object both our force and gravity force are occurred so it is easy to pull but hard to push.

Stone required less energy to rolling than lifting upward. It due to gravitational force of attraction acting on stone.

Always remember that gravitational pull always tries to pull an object going upward downward so more work is done in lifting dan in rolling.

The energy required to roll it down is less than the energy it required to lift it up.

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.

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.

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.