I have just started a calculus book, and I cant figure out how to solve this problem: 1. The problem statement, all variables and given/known data The landing velocity of an airplane (i.e., the velocity at which it touches the ground) is 100 mi/hr. It decelerates at a constant rate and comes to a stop after traveling 1/4 mile along a straight landing strip. Find the deceleration or negative acceleration. 2. Relevant equations 3. The attempt at a solution a = x v = xt + C v = xt + 100 s = (x/2)t^2 + 100t + C 1/4 = (x/2)t^2 +100t I'm not sure what to do next.