Posted by kinematics on Monday, February 11, 2008 at 11:57pm.
An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at +40 ft/s2. After some time t1, the rocket engine is shut down and the sled moves with constant velocity v for a time t2. If the total distance traveled by the sled is 17 500 ft and the total time is 90 s, find the times t1 and t2

physics  drwls, Tuesday, February 12, 2008 at 12:10am
t1 + t2 = 90
(1/2)a*t1^2 + a*t1*t2 = 17,500
You know that a = 40. That leaves you with two equations in two unknowns to solve.