Question

If suddenly the gravitational force of attraction between the earth and a moon becomes zero, then the moon will
1. continue to move in this orbit with same velocity
2. move tangentially to the original orbit in the same velocity
3. become stationary in its orbit
4. move towards the earth

Answer 1

Correct Answer - Option 2 : move tangentially to the original orbit in the same velocity

The correct answer is move tangentially to the original orbit in the same velocity.

• When gravitational force becomes zero, then the centripetal force of the moon becomes zero so, the moon will move tangentially to the original orbit with the same velocity because of the conservation of momentum and energy. 

• Centripetal Force
  • A body performing circular motion is acted upon by a force that is always directed towards the center of the circle.
  • Work done by a centripetal force is always zero.
  • Any forces found in nature such as frictional force, gravitational force, the magnetic force may act as a centripetal force.
• The law of conservation of energy states that energy can neither be created nor be destroyed. It only converted from one form of energy to another.
• The law of conservation of momentum states that the momentum of a system is constant if no external forces are acting on the system.
• Momentum is defined as the product of the mass of the body and the velocity of the body. Simply we can say that Momentum is the mass in motion.