the kinetic energy of the moving car is proportional to the square of the velocity
... this is the energy that is dissipated by the skidding ... at a constant rate
so a car going 2.5 times as fast ... will skid 2.5^2 times as far
2.5^2 = 6.25 ... 6.25 * 14 = ?
This question is typical on some driver’s license exams: A car moving at 40 km/h skids
14 m with locked brakes.
How far will the car skid with locked brakes
at 100 km/h? Assume that energy loss is due
only to sliding friction.
Answer in units of m
2 answers
d = (100/40)^2 * 14m = 2.5^2 * 14 = 87.5 m.