A worker must raise a 20 kg crate from the floor to a loading shelf located 2.0 m higher
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
A worker must raise a 20 kg crate from the floor to a loading shelf located 2.0 m higher. Two different methods are considered:
• Method I: Lift the crate straight upward at constant speed.
• Method II: Push the crate at constant speed up a friction-free ramp that is 4.0 m long and rises uniformly to the same shelf height.
Assume the crate moves only under the influence of the applied push and Earth’s gravitational force; neglect friction and air resistance.
(a) Calculate the work done on the crate by Earth’s gravitational force for Method I.
(b) Calculate the work done on the crate by Earth’s gravitational force for Method II.
(c) Compare the results from parts (a) and (b). Explain what this comparison reveals about the relationship between the work done by gravity and the specific path taken.