A particle with a mass of 0.210kg is attached to a horizontal spring with a force constant of 0.84 N/m. At the moment t=0, the particle has its maximum speed of 5m/s and is moving to the left. (Assume that the positive direction is to the right.) Determine the particle's equation of motion, specifying its position as a function of time (use the following as necessary: t) F = -kx F = ma What I did was: -0.84x = 0.210a -0.84x = 0.210[(v - 5)/t)] -0.84x = 0.210[(x/t - 5)/t] I still can't isolate for x, and i dont know if what i am doing is right. Please help.