1. The problem statement, all variables and given/known data A person places a 2.2kg truck against a horizontal spring (k=2300N/m) on a frictionless horizontal surface. The spring is compressed 15cm and released. a) How much energy is stored in the spring just before the truck is released? b) What is the velocity of the truck after it is "launched" (leaves the spring)? c) If the spring inadvertently becomes hooked to the the bumper of the truck, what will be the period of the truck's oscillation? d) As in part c, if the spring becomes hooked to the back of the truck calculate the location of the truck 0.31 seconds after the truck is released? 2. Relevant equations 3. The attempt at a solution i tried to use the pe=1/2kx^2 equation for the first part but im forgetting what is k is again. Also my weakness is in oscillation questions because after 3 months of summer vacation im forgetting if we would use KE=1/2mv^2. Im utterly confused with thi problem.