My Experiment consists of two balls of different masses falling together in the y axis from the same fixed height.Im researching how mass of the smaller ball affects its rebound height. My method of adding mass however was very crude as I stuck weights on using tape. This surely altered the aerodynamics of the ball and I did notice an increased spin on the ball, (unbalanced weight arrangeent?). What does this mean? The energy given by the larger ball is used up in giving spin and velocity to the samleer ball hence the rebound height is lower than what it hypothetically should have been? My readings are very far off the elastic model i formulated, barely even following the trendline. How do i explain this?