Calculating Total Length of Car's Breaking Path with a=4 m/s^2

[Hristijan1992]

Homework Statement

During the testing of the break of car, observed that in the first second of the start of breaking the car past one fifth of the total path. What is the total length of the traveled way during the breaking, if the acceleration is a=4 m/s^2 ?

Homework Equations

The Attempt at a Solution

https://www.physicsforums.com/newthread.php?do=newthread&f=154

 

[tiny-tim]

Welcome to PF!

Hi Hristijan1992! Welcome to PF!

(btw, it's "brake" and "braking" )

erm … your solution hasn't come out, the link isn't working!

I assume you used the standard constant acceleration equations?

Show us what you get. ​

 

[Hristijan1992]

The solution is : s=a/2(sqrt(5)/(sqrt(5)-2))^2 but i don't know how can i solve the problem...

 

[tiny-tim]

Hi Hristijan1992!

(have a square-root: √ and try using the X² icon just above the Reply box )

Call the stopping distance s, and write one of the standard constant acceleration equations for distance = s (with v_f = 0), and another for distance = s/5 (with t = 1).

Show us what you get. ​

 

[Hristijan1992]

i can't solve it ... Please if anyone can show me what is the problem... i must solve it ...

 

[tiny-tim]

Sorry, on this forum you have to do it yourself.

Show us what you've tried, and where you're stuck, and then we'll know how to help! ​

 

[Hristijan1992]

yay :D i solve it. Thank you very much