# How can I tell if a given car can go from 0 to x MPH over a distance of d feet?

AxiomOfChoice
What information do I need about the car to make this determination?

(Specifically, I'm talking about a 2000 VW Golf.)

## Answers and Replies

Homework Helper
What information do I need about the car to make this determination?

(Specifically, I'm talking about a 2000 VW Golf.)
You need to know how long it takes for the car to accelerate from 0-60 mph. This is kind of a standard for comparing acceleration of cars.

That will enable you to determine the approximate average acceleration (there is some inaccuracy because the car may not accelerate evenly). From that you can determine the time it would take to reach x MPH. From that you can determine the distance covered in that time. Then you can compare it to the distance d.

AM

AxiomOfChoice
You need to know how long it takes for the car to accelerate from 0-60 mph. This is kind of a standard for comparing acceleration of cars.

That will enable you to determine the approximate average acceleration (there is some inaccuracy because the car may not accelerate evenly). From that you can determine the time it would take to reach x MPH. From that you can determine the distance covered in that time. Then you can compare it to the distance d.

AM

Ok, thanks. This was certainly my first instinct, but I wanted a second opinion. I managed to complete the calculation. Thanks again for your help!

You need to know the force applied by the tires to the road. To do that, you need to know the engine torque, the drivetrain ratio (which will change if you shift gears on your way to X mph), the tire diameter. You need to know something about the tires (or assume something, like 'no slip').

I think the assumption of constant acceleration is not to accurate.

Homework Helper
It's difficult to accurately predict based on just simple numbers. You'd need to know the amount of grip, which affects the launch, as well as the gearing, shift times, torque curve of the engine, weight of car, ...

Fish4Fun
Well I think all you need to know is when it was dropped ;-)

Fish