Distance it takes to stop HELP

  • Thread starter jo3jo3520
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In summary, the minimum stopping distance for a car traveling at a speed of 30 m/s is 60 m, including the distance traveled during the driver's reaction time of 0.50 s.
  • #1
jo3jo3520
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The minimum stopping distance for a car traveling at a speed of 30 m/s is 60 m, including the distance traveled during the driver's reaction time of 0.50 s.

(a) What is the minimum stopping distance for the same car traveling at a speed of 50 m/s?


Vf^2 = Vi^2 +2ax


So i would be solving for X here right? so the car is not accelerating do i plug in 0 for a?

This is what i have so far

0=50^2+2(a)(x) where does the .5 reaction time come into play?
 
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  • #2
jo3jo3520 said:
The minimum stopping distance for a car traveling at a speed of 30 m/s is 60 m, including the distance traveled during the driver's reaction time of 0.50 s.

(a) What is the minimum stopping distance for the same car traveling at a speed of 50 m/s?


Vf^2 = Vi^2 +2ax


So i would be solving for X here right? so the car is not accelerating do i plug in 0 for a?

This is what i have so far

0=50^2+2(a)(x) where does the .5 reaction time come into play?

You're right that the .5sec reaction time needs to be accounted for.

But you need to first account for it from the first measurements.

The Total distance traveled to stopping included .5*(30m/s). Then the total change in velocity occurred over that smaller distance - not including reaction time.

Now for the 50m/s case how long to stop if you use the deceleration from the first measured stop? From that distance you then need to add the (50m/s)*.5sec to get your total distance.
 
  • #3
ok so .5*30 = 15 but I am confused on what to do with that? you said "Then the total change in velocity occurred over that smaller distance - not including reaction time." ?
 
  • #4
am i supposed to do 30/15? and where in the equation do i plug this number in?
 
  • #5
help anyone?
 
  • #6
jo3jo3520 said:
ok so .5*30 = 15 but I am confused on what to do with that? you said "Then the total change in velocity occurred over that smaller distance - not including reaction time." ?

So the car deceleration alone was only over 45m and not 60m then wasn't it? Now figure the deceleration performance of just the car.

You have Velocity and distance, so find acceleration "a" that gives you that deceleration over 45m.
 
  • #7
Either I am just really dumb or not understanding but i give up. thank you for your help
 

1. What is the distance it takes to stop a car traveling at a certain speed?

The distance it takes to stop a car depends on several factors, including the speed of the car, the condition of the road, and the condition of the car's brakes. However, on average, it takes a car traveling at 60 miles per hour about 300 feet to come to a complete stop.

2. How does the weight of a car affect the distance it takes to stop?

The weight of a car does affect the distance it takes to stop. The heavier the car, the more momentum it has, making it harder to slow down and stop. This means that a heavier car will typically require a longer distance to come to a complete stop compared to a lighter car.

3. Does the type of tires on a car impact the distance it takes to stop?

Yes, the type of tires on a car can impact the distance it takes to stop. Tires with better traction, such as winter tires or tires with a deeper tread, can provide more grip on the road and help a car stop in a shorter distance compared to worn or bald tires.

4. How does the condition of the road affect the distance it takes to stop?

The condition of the road can greatly impact the distance it takes to stop a car. Roads that are wet, icy, or covered in debris can decrease the amount of friction between the tires and the road, making it harder for a car to stop. This is why it is important to adjust your driving speed and distance from other cars in these conditions.

5. Can the distance it takes to stop be affected by the driver's reaction time?

Yes, the driver's reaction time can affect the distance it takes to stop a car. The longer it takes for a driver to recognize a hazard and react by pressing the brakes, the longer the car will travel before coming to a complete stop. This is why it is important for drivers to stay alert and focused while driving to minimize their reaction time in case of an emergency.

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