Two small balls with masses 3M and M hang on elastic massless rubber bands (with the M ball attached to and suspended beneath the 3M ball with one rubber band; the 3M ball is suspended from the ceiling by a seperate rubber band). When the band between the balls is cut, what are the accelerations of the balls immediately after?
The Attempt at a Solution
I think the M ball would simply move downward at acceleration g=9.8 m/s^2. But would the 3M ball move upwards due to the release of the tension when the rubber band is cut? And would that upward acceleration be equal to the force of gravity on the M ball? How do you take the force of gravity on the 3M ball into account?