## anonymous 4 years ago a car is traveling in a straight line and decelerating at a constant rate. after 3.2 seconds it has traveled 88m and slowed to a speed of 27 m/s what is the initial speed i got 52 m/s

1. anonymous

$v^2-2as=u^2$

2. perl

what does s and u stand for?

3. anonymous

Put $a=\frac{v-u}{t}$

4. anonymous

s distance u initial velocity

5. anonymous

and the plug a back into the equation that is what i did but im not sure if my math is right

6. anonymous

other people had like 97m/s which didnt make sense to me

7. perl

v is final velocity, u is initial velocity

8. anonymous

Better use $s=ut+\frac{1}{2}at^2$

9. perl

so youre using kinematic equations under the assumption that acceleration is constant

10. perl

might as well write them all out :)

11. anonymous

Help me

12. perl

youre doing good

13. perl

there are 4 kinematic equations under constant acceleration

14. anonymous

Gotto go i told everything would need to do this problem

15. anonymous

i used x=xknot+vknot(t)+.5a(t)^2 where x= position, v=velocity a=acceleration and t= time

16. anonymous

i solved for and the plugged it into v=vknot+a(t) and solved for vknot

17. anonymous

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