General Knowledge - Physics - Discussion

In lifting the angle is 90, hence W = mg; w = m * sin90.
Therefore, at the angle for example, 10, w = m * sin10, which less than when the angle is ninety given there is no friction.

The Correct answer is D.

Pulling is easier than pushing.

The work is the same. Assuming initial velocity is equal to a final velocity in both situations (that is, they all are zero), then neither experienced a change in kinetic energy. I am assuming that they both are moved to the same height because this would be totally illogical and uninteresting, as well as unsolvable if they were not. Therefore work done by gravity in both is mg, they both are moved same distance vertically and gravity is opposing them the entire time, therefore, equal and opposite work had to be done. Now, considering friction, it's totally irrelevant. The stone is rolled, therefore friction is not doing work of any kind it is simply providing the torque necessary to cause the angular velocity to remain constant.

Since the perpendicular distance between stone and earth is less than slope. Hence force between stone and earth through the path of the slope is less than that between same through the perpendicular path by universal gravitational law. And the distance is more for slope and less for perpendicular for the same case. So, energy is constant ie, mgh. The coefficient of friction makes us easy to roll and increases power. I think C is correct.

Much effort is been applied when lifting, less work is done when rolling.

I think work done in both cases are the same, if and only if the inclined surface is frictionless because the conservative force does not depend on the path of the object.

Work done in rolling is less than lifting it up because the work done is force per distance of an object.
Here the force becomes directly proportional to the distance while in lifting the force becomes inversely proportional to distance because of potential energy possessed.

In case rollin their force component get resolved but in in case of lifting single force component act over body so according to work formula as we know that:

W = fdcoso.

Force component not resolved that's why value of cos increased. So over all work increased. against gravity f-is force d-is displacement.

Definitely the correct option is D, if we thrown the stone vertically we lost more effort and the stone is directly return to the original position due to the gravity but when you thrown the stone incline there is no gravity and friction. So the work done in lifting is less than in rolling.

I think that if we lift this stone, we must effort a lot but if we roll it, we must effort a little. And so the work done is directly proportional to the effort.