# Homework Help: Stuck on simple constant accel. problem

1. Aug 28, 2011

### resjsu

1. An antelope moving with constant acceleration covers the distance between two points 70.0 meters apart in 7.00 seconds. It's speed as it passes the second point is 15 m/s.
A] Find speed at first point. B] What is the acceleration?

2.
From text University Physics 11th edition question 2.21 page 70
Eqns of motion with constant acceleration
Vx=Vox+AxT
X=Xo+VoxT+1/2AxT
Vx2=Vox2+2Ax(X-Xo)
X-Xo=((Vox+Vx)/2)T

3. I have tried but nothing worth posting. I'm stuck on the fact that I cannot find how to use the average Velocity to find the instantaneous Velocity at point 1, Thank you!.

2. Aug 28, 2011

### lewando

You know T, Vx, and (X - X0). One of the four equations will allow to to determine V0x directly.

3. Aug 28, 2011

### resjsu

Crap! For some reason I was stuck on having to find the original velocity by finding the limit as time went down to zero.... So I was plugging in 0.01, 0.001 and was getting ridiculous answers. Thank you! I've posted one more problem I cannot seem to get my head around.