An electric motor operates in two distinct modes while lifting a small mass vertically
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
An electric motor operates in two distinct modes while lifting a small mass vertically.
• Mode I: The motor supplies a constant 50W of power for the first 5.0s.
• Mode II: Immediately afterward, it supplies a constant 120W of power for the next 3.0s.
Assume all the motor’s output power is converted into gravitational potential energy of the mass.
(a) Calculate the work done by the motor during Mode I.
(b) Calculate the work done by the motor during Mode II.
(c) Determine the total increase in gravitational potential energy of the mass after the full 8.0s of operation, and state the result with appropriate units.