1. The problem statement, all variables and given/known data An automobile moving along a straight track changes its velocity from 40 m/s to 80 m/s in a distance of 200 m. What is the (constant) acceleration component of the vehicle during this time? 2. Relevant equations 3. The attempt at a solution I try to solve this problems with 2 different approaches. First : Since we don't know the time (t) , we need to calculate the time. If we assume the initial position as xi=0 and VxAvg as 40 m/s , then I am getting t=5 sec. But that doesn't help me to reach the final answer. I ended up with 8.0m/s2. Second: If I didn't care about the time(t) and if I use Velocity as a function of position eq ( assuming xi =0 ) then I am getting the correct answer which is 12m/s2. My question is "Can I assume the initial position is xi=0? IS IT CORRECT?" Thank you!!