Question

A 3000kg truck moving at a speed of 72km/hr stops after covering some distance . Calculate work done by force

Answer 1

Answer: Kinetic energy is same thing as work done. Therefore Formulas of both will also be same. Therefore work-done=1/2mv^2

Therefore- m=3000kg, v=72km/h

First convert all the terms in SI units

Therefore- mass is in SI

72km/h=20m/s

Therefore- work done=1/2mv^2

Therefore- 1/2*3000*(20)^2

=1500*400

Ans=6,00,000