Equations for Accelerated Motion Problem

[Medgirl314]

Homework Statement

Starting from rest, a car accelerates for 8 seconds with a constat acceleration. During this time it travels 121 meters. Find its velocity at the end of the 8 seconds.

Homework Equations

a=(2x)t^2
Vavg=(Vinital+Vfinal)/2

The Attempt at a Solution

First, I found the average velocity by deviding 121 by 8 to get 15.125.

Second, (with instruction from my physics teacher), I found the acceleration.
a=(2x)*8^2
a=(2*121)/64
242/64=3.78
a=3.78 m/s


Then, knowing the acceleration, I found the final velocity.

Vavg=(0+Vfinal)/2
15.125=(Vfinal)/2
15.125*2=30.25 m/s
So, Vfinal should be 30.25 m/s, correct? I'm fairly sure of my answer, but I like to check before I turn it in.


Thanks in advance for a reply!

 

[NihalSh]

seems good to me!...Answer is right.

 

[Medgirl314]

Thank you! You are so helpful.