A compact car of mass is travelling on a level roadway when its translational kinetic…
PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
A compact car of mass 1.20×103kg is travelling on a level roadway when its translational kinetic energy is measured to be 3.60×105J. Air resistance and rolling friction are negligible for the time interval considered.
(a) Calculate the speed of the car corresponding to the stated kinetic energy.
(b) While approaching a red light, the driver lightly applies the brakes and reduces the car’s speed to 13ms−1. Determine the car’s new translational kinetic energy.
(c) Compute the percentage of the car’s original kinetic energy that the braking system must remove during this deceleration. Explain the physical significance of this percentage in the context of automotive safety.