A platform (black) is suspended from a fixed support by a rubber band. Weight can be added to the platform. When the red stick is pulled away, the platform with its weight will oscillate vertically and eventually come to rest at its equilibrium position. The goal of the problem is to take data to find the spring constant of the rubber band and to find the mass of the platform. For the latter, you'll need one measurement other than those described below.
With platform held in place by the stick, the rubber band is unstretched. Click the play buttom to pull the stick away quickly and let the platform fall. After the platform reaches its resting position, read the position to the nearest 0.001 m. (In order to make the motion damp more quickly, increase the value of the damping coefficient.) Add 0.1 kg of mass to the plaform and click Reset. Then play the animation to see the new equilibrium position. Record the reading. Continue to add mass in increments of 0.1 kg and measure the equilibrium position each time. Tic marks are placed every 0.05 m to aid in taking readings.