Points to Remember:
- Work done is the product of force and displacement in the direction of the force.
- Work done is independent of the path taken (for conservative forces like gravity).
- Work done is independent of the time taken.
- Work done is directly proportional to the weight (force) of the body lifted.
Introduction:
This question pertains to the concept of work in physics. Work, in its simplest form, is defined as the energy transferred to or from an object via the application of force along a displacement. The formula for work is: Work (W) = Force (F) x Displacement (d) x cos(θ), where θ is the angle between the force and displacement vectors. In this case, we are lifting a body vertically against gravity, so θ = 0 and cos(θ) = 1. The question asks us to identify the factor that does not affect the amount of work done in lifting a body. This requires an analytical approach focusing on the physics of work.
Body:
A. The Path Along Which You Lifted the Body:
The work done in lifting the body depends only on the vertical displacement, not the path taken. If you lift the body straight up or along a curved path, as long as the final vertical displacement is the same, the work done against gravity remains the same. This is because gravity is a conservative force; the work done is path-independent. Lifting the body in a zig-zag pattern would require more effort overall, but the work done against gravity remains unchanged.
B. The Time Taken by You in the Process:
The time taken to lift the body does not affect the total work done. Work is a measure of energy transfer, not the rate of energy transfer (which is power). You could lift the body slowly or quickly; the total work done against gravity remains the same. A slower lift implies less power, while a faster lift implies more power, but the total work remains constant.
C. The Weight of the Body:
The weight of the body directly affects the work done. Weight is the force due to gravity (F = mg, where m is mass and g is acceleration due to gravity). A heavier body requires a greater force to lift it, resulting in more work done. This is directly evident in the work formula: a larger force (weight) leads to a larger amount of work for the same displacement.
D. Your Own Weight:
Your own weight is irrelevant to the work done in lifting the body. Your weight does not contribute to the force required to lift the object against gravity. The work done is solely determined by the force required to overcome the gravitational force acting on the body being lifted, and the vertical distance it is lifted.
Conclusion:
The amount of work performed in lifting a body from the ground onto a table does not depend on (A) the path along which you lifted the body or (B) the time taken by you in the process. The work done is directly proportional to (C) the weight of the body. (D) Your own weight is irrelevant to the calculation of work done on the body being lifted. Therefore, the correct answers are (A) and (B). Understanding the distinction between work and power is crucial in grasping this concept. Focusing on the fundamental principles of physics, particularly the conservative nature of gravitational force, allows for a clear and accurate assessment of work done in such scenarios. This understanding is vital for various applications in engineering and other fields.