6.A body crosses the topmost point of a vertical circle with critical speed. What will be its acceleration when the string is horizontal ?

7.A sphere is rolling without slipping on a horizontal plane. The ratio of its rotational kinetic energy and translational kinetic energy is

8.Which of the following is conserved when the torque acting on a system is zero ?

9.If the Earth shrinks to half of the present radius, without any change in mass, then the duration of day and night becomes

10.A body rolls down an inclined plane. If its kinetic energy of rotational motion is 40% of its kinetic energy of translation, then the body is