1. The problem statement, all variables and given/known data A runner hopes to complete the 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must then accelerate at 0.20 m/s2 for how many seconds in order to achieve the desired time? 2. Relevant equations vf = vo + at avg velocity = (vf + vo) /2 d = vo)t + (1/2) at2 vf2 = vo2 + 2ad 3. The attempt at a solution Most of my solutions just wind up at 0 = 0 or a = a.... In other words, I'm not doing anything wrong, but it's that I can't think of any other way to solve it. d1 = 8900 m t = 1620 s d2 = 1100 m avg velocity = 8900 / 1620 = A (I took this route so I could find the instantaneous velocity at t = 1620s, which I though would lead up to another part that could solve the problem) A = (vf+ vo) / 2 2A - vf = vo a = [vf - (2A - vf)] / t a = (2vf - 2A) /t vf2 = (2A - vf)2 + 2[ (2vf -2A) /t] d1 (which results in) 0 = 0 I've been thinking about this problem for a loooong time, but I can't figure out another way to solve it.