1. The problem statement, all variables and given/known data A 50-gram mass is accelerated from rest be a compressed spring (k = 1800 N/m), sending it on a journey along a frictionless loop-de-loop of radius 0.324 m. What minimum amount of initial compression of the spring is required if the mass is to remain in contact with the track at the top of the loop? 2. Relevant equations centripetal acceleration = (v^2)/r F = ma F = kx (Hooke's Law) 3. The attempt at a solution The velocity required at the top of the loop: v = sqrt( 9.80m/s^2 * 0.324 m) = 1.782 m/s Since the spring constant k is already known, we'd just need to determine F and use Hooke's Law to solve for x. But I can't figure out how to determine the force required to make push that mass and give it that velocity at the top of the loop.