A child swinging on a swing in sitting position, stands up, then the time period of the swing will

Initial angular velocity of a circular disc of mass $$M$$ is $${\omega _1}.$$ Then two small spheres of mass $$m$$ are attached gently to diametrically opposite points on the edge of the disc. What is the final angular velocity of the disc?

If suddenly the gravitational force of attraction between Earth and a satellite revolving around it becomes zero, then the satellite will

If mass-energy equivalence is taken into account, when water is cooled to form ice, the mass of water should