1)A stone of mass 20g is released from a catapult whose rubber has been stretching through 4cm. if the force constant of the rubber is 200Nm^-1, calculate the velocity with which the stone leaves the catapult 2)A spiral spring is compressed by 0.02m. calculate the energy stored in the spring, if the force constant is 400Nm^-1​

less than one you can't create energy

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.