Question

You are participating in an unusual drag race. You start from rest and try to cover a straight quarter-mile (400 meters, for the purpose of this problem) in the shortest time possible. Your car is very well built so it can achieve speeds of up to 360 km/h. It is equipped with a very powerful engine and an excellent anti-lock braking system. The coefficient of static friction between the wheels and the road is about 1.2 (the drag-race tires are made of very soft rubber which is pre-heated before the start by spinning the wheels; as a result, the wheels achieve the effective coefficient of friction greater than 1). However, there is a crucial difference: you are required, for publicity purposes, to come to a dead stop at the finish line (in a typical drag race, you would fly right through that finish line!). speed up at the maximum possible rate for the first half of the distance; then slow down at the same rate What is the shortest possible time needed to complete the race (in seconds)?

Answer 1

i just solved a similar question. Although the asker has written it poorly, his/her question is very similar to yours.

http://openstudy.com/study#/updates/51e2b068e4b0d9a104dbf5ba

Your parameters s and a will be

s=400m
a=1.2g =12m/s\(^{2}\)