General Knowledge - Physics - Discussion
Discussion Forum : Physics - Section 1 (Q.No. 2)
2.
It is easier to roll a stone up a sloping road than to lift it vertical upwards because
Discussion:
84 comments Page 4 of 9.
Samsudeen lastborn said:
1 decade ago
(lifting and pulling) both will experience an opposition force. In lifting a force of gravity will be oppose while in that of pulling it experience d frictional force. i.e work done in lifting will be more than that of the pulling.
Sharma said:
9 years ago
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.
Curiosity said:
1 decade ago
Since in a simple machine effort * effort arm = load * load arm.
In this case it is effort * hypotenuse of the rt angled triangle = load * perpendicular.
But perpendicular<hypotenuse.
Therefore effort<load.
In this case it is effort * hypotenuse of the rt angled triangle = load * perpendicular.
But perpendicular<hypotenuse.
Therefore effort<load.
Vintoni said:
9 years ago
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.
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.
Chua said:
8 years ago
The answer should be C. Work done is the same (neglecting frictional force). Pushing force is mgsin but pushing distance is mgh/sin. So work done work done is still mgh in both cases.
(2)
John said:
1 decade ago
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.
So the normal force at a shorter distance will be more effective in lifting than a vector's of normal force in rolling.
Mridul said:
1 decade ago
Work done in lifting is not more or less we feel it more due to the gravitational force acting on that object in same way we have to push it so no force required against gravity.
Yohan A said:
9 years ago
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.
Subradeep said:
1 decade ago
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.
Pavankumar said:
8 years ago
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.
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