General Knowledge - Physics - Discussion

Answer is D. Because for lifting objects it has more force of gravity and for rolling objects, it is less, friction of rolling is less. So it is easy to roll the stone.

The exact answar should be D. Because in vertically upward we have to force against mg. But in rolling the opposite force is mgsin. And we are putting force against mgsin. mgsin<mg. So rolling is less than vertically.

Answer is D, because the ball rolling is against the gravity that's why it's less.

(Zain said: (Nov 25, 2016).

The work doesn't change in both cases, it's true the gravitational force will less in the second case but the distance will be greater so that the work is same. ).

Fgs, gravitational force is constant and only vertical distance is relevant so it's the same too.

So work is same. Answer is supposed to be freaking 'c'.

Basic physics c'mon guys.

The questioned mentioned 'rolling'. Thus friction does not apply at all and as seen in many comments, work= force x distance, force is mg and is constant. Distance traveled is the same too as vertical height achieved is equal. (Horizontal distance of slope is not counted).

I agree with the given answer i.e D.

The work doesn't change in both cases, it's true the gravitational force will less in the second case but the distance will be greater so that the work is same.

For me, it is difficult to say the difference between C and D. Which one is the truth? Someone explain it clearly to understand.

At the bottom the energy of the stone is X.

At the top X+m.g.h (m= stone mass, g= gravitational force m, h= height of the hill).

So for the stone, it doesn't matter how it is brought up. Somebody must "add" that potential energy to the stone.

What must a stone carrier overcome? By rolling, the friction of the stone and the hill and the constant lifting of (part) of the stone weight to make it roll. He must add the potential energy and overcome the friction.

By lifting and walking the carrier must add all the potential energy the stone gained at the top, But no friction is involved.

So how D is the right answer?