Trying to find the displacement

Jun 2017
15
0
Hi,
I'm hoping to get some clarification on this. I'd like to see if I did it right, and if not then I'd really like to know what I did wrong.
A car is traveling at 20.83m/s , it takes 3.4s to stop, what is the displacement?

d=1/2(V1+V2)t

= 1/2(20.83m/s+0m/s)(3.4)
= 1/2(70.83)
= 35.42m

It seems right, but in my lesson text they say that formula only applies to situations of constant velocity, and I don't believe this is constant velocity.

I appreciate any help, thanks very much.
 

ChipB

PHF Helper
Jun 2010
2,369
294
Morristown, NJ USA
Your formula is correct, though I get 35.41m. It applies to situations of constant acceleration.