A student claims, “If the pulling force on a cart remains unchanged
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A student claims, “If the pulling force on a cart remains unchanged, then doubling the cart’s speed will automatically double the power needed.” Examine the correctness of this statement.
(i) State the physical relationship that links power, force and velocity when the force acts along the direction of motion.
(ii) Using this relationship, explain whether the student’s claim is correct. Give a clear reason in words.
(iii) If the power is fixed instead of the force, discuss qualitatively how the cart’s speed would change when the pulling force increases because the cart is loaded with extra goods.