What is the hypothesis for Lift an Ice Cube.

When we sprinkle salt onto the ice cube, the state of equilibrium is disrupted. The salt molecules dissolve and join the water molecules thus changing the water's rate of freezing. The rate of melting is now much faster than freezing hence causing the ice to melt.

Explanation: Hope this helps

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.