# What is the stopping distance!

I don't understand these words: stopping distance and reaction time! Can anyone show me how to solve or the formula of stopping distance and reaction time!

What are the factors affect the stopping distance?
Like, there is a car is traveling at 70 m/hr, and its reaction time is 2 seconds, what is the stopping distance? --> how to calculate the stopping distance?

Thank you very much!

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berkeman
Mentor
I don't understand these words: stopping distance and reaction time! Can anyone show me how to solve or the formula of stopping distance and reaction time!

What are the factors affect the stopping distance?
Like, there is a car is traveling at 70 m/hr, and its reaction time is 2 seconds, what is the stopping distance? --> how to calculate the stopping distance?

Thank you very much!
Reaction time is the time between the signal to stop, and the beginning of decelertion. Like when you approach an intersection, and the traffic light turns yellow. You see that, and it takes you about a second to react to it and get on the brakes.

So your velocity is constant for part of the time interval, and then you decelerate for the rest of the time interval.

Does that help?

Reaction time is the time between the signal to stop, and the beginning of decelertion. Like when you approach an intersection, and the traffic light turns yellow. You see that, and it takes you about a second to react to it and get on the brakes.

So your velocity is constant for part of the time interval, and then you decelerate for the rest of the time interval.

Does that help?
It's very helfull but I want to ask you that are there some factors that affect the stopping distance? like, time, speed.. or something like that?

Is there a formula to calculate the stopping distance in my example above?

berkeman
Mentor
It's very helfull but I want to ask you that are there some factors that affect the stopping distance? like, time, speed.. or something like that?

Is there a formula to calculate the stopping distance in my example above?
Stopping distance is shorter if the reaction time is faster (right?) and if the deceleration is greater (like for higher-performance cars and sportbikes).

Deceleration rate varies quite a bit between vehicles (and road conditions). I googled California DMV Stopping Distance, and got some good hits. The Department of Motor Vehicles (DMV) includes this type of (typical) info in the driver training documentation. Here is a hit off the hit list that should give you some ideas:

http://www.skytran.net/09Safety/03sfty.htm [Broken]

.

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