Which requires more work, increasing a car's speed from 0 mph to 30 mph or from 50 mph to 60 mph?
A) 50 mph to 60 mph
B) 0 mph to 30 mph
C) It is the same in both cases.

Question

Quizplus · Accepted Answer

The work done on an object is related to the change in its kinetic energy, which is given by the formula $ \frac{1}{2}mv^2 $, where $ m $ is the mass of the object and $ v $ is its velocity. Increasing a car's speed from 50 mph to 60 mph requires changing its kinetic energy from $ \frac{1}{2}m(50)^2 $ to $ \frac{1}{2}m(60)^2 $, which represents a larger increase in kinetic energy (and thus more work) than increasing its speed from 0 mph to 30 mph, which changes its kinetic energy from 0 to $ \frac{1}{2}m(30)^2 $.

Which Requires More Work, Increasing a Car's Speed from 0