List of top Physics Questions on Centre of mass asked in BCECE

A stationary object is released from a point P a distance 3R from the centre of the moon which has radius R and mass M. Which one of the following expressions gives the speed of the object on hitting the moon ?

The length of a metal wire is l₁, when the tension in it is T₁, and is l₂ when the tension is T₂. The natural length of wire is