Question

Choose the only incorrect statement from the following:

• A. The position of the centre of mass of a system of particles does not depend upon the internal forces between particles.
  
• B. The centre of mass of a solid may lie outside the body of the solid.
• C. A body tied to a string is whirled in a circle with a uniform speed. If the string is suddenly cut, the angular momentum of the body will not change from its initial value.
• D. The angular momentum of a comet revolving around a massive star, remains constant over the centire orbit.
  

Answer 1

The correct option is C A body tied to a string is whirled in a circle with a uniform speed. If the string is suddenly cut, the angular momentum of the body will not change from its initial value.

The only incorrect statement is (c). Since no external torque acts on the body even after the string is cut, the angular momentum will remain unchanged.