How Do You Calculate Stopping Distance?

[zeo2396]

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!

 

[berkeman]

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?

 

[zeo2396]

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]

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

.

 

[rwisz]

The stopping distance is the distance that a vehicle travels from the moment the brakes are applied until it comes to a complete stop. It is influenced by several factors, including the vehicle's speed, the driver's reaction time, and the road conditions. The formula for calculating stopping distance is: stopping distance = reaction time x speed + braking distance. The braking distance is determined by the vehicle's mass, speed, and the friction between the tires and the road.

To calculate the stopping distance in your example, we would first need to convert the speed from miles per hour to meters per second. This can be done by dividing the speed by 2.237. So, 70 miles per hour would be equal to 31.3 meters per second.

Next, we would need to calculate the braking distance. This can be done by using the equation: braking distance = (speed^2) / (2 x deceleration). The deceleration is a measure of how quickly the vehicle can slow down, and it is typically given in meters per second squared. For a car, a common deceleration value is 9.8 meters per second squared. So, plugging in our values, we get: braking distance = (31.3^2) / (2 x 9.8) = 484.3 meters.

Finally, we can calculate the stopping distance by adding the braking distance to the reaction time multiplied by the speed. In this case, it would be: stopping distance = (2 seconds x 31.3 meters per second) + 484.3 meters = 546.6 meters.

It is important to note that this is a simplified calculation and may not account for all factors that can affect stopping distance. Other variables, such as weather conditions and the condition of the vehicle's brakes, should also be considered when determining the stopping distance.