Which of the following quantities remains conserved when an object moves under the gravitational pull of another object?

Correct option is D

The correct answer is (d) Angular momentum and mechanical energy.
• When a body moves under the influence of gravity (a central force), angular momentum and total mechanical energy remain conserved.
• Gravitational force is conservative, meaning work done is path-independent and energy can convert between potential and kinetic forms without loss.
Information Booster:
• Conservation of angular momentum: L=mvrL = mvrL=mvr remains constant for central forces.
• Mechanical energy =K.E+P.E= K.E + P.E=K.E+P.E remains constant in absence of non-conservative forces.
• Law of Conservation of Energy applies universally in physics.
• Example: Planetary motion follows Kepler’s Laws, derived from these conservation principles.
• Gravity is an example of an inverse-square law force.
Additional Knowledge:
• Linear momentum is not conserved when external forces (like gravity) act.
• Angular momentum conservation explains the rotation of planets and satellites.
• Kinetic energy changes with velocity, but total mechanical energy stays constant.
• These laws are based on Newtonian Mechanics and verified through celestial observations.