The distance a car will skid after its brakes lock can be modelled by the equation d=kv^2, where d is the stopping distance in metres, k is a constant based on road conditions and v is the velocity of the car in metres per second at the moment the brakes lock.

Question

1.) if a car skids 79 m when k= 0.031 how fast was the car travelling? Answer= 50m/s but I can't figure out how to get the answer.

Answer 1

d=kv^2

v=sqrt(d/k)=sqrt(79/.031)=sqrt(2541)=about 50 m