The quantity of motion of a body is its

1. Analyze the question "Quantity of motion" is the classical name for a physical quantity that combines how much matter a body has with how fast it moves.

2. Explain the concept Isaac Newton described momentum as the "quantity of motion" of a body. It depends on two things:

• the mass of the body (m)
• the velocity of the body (v)

Momentum (p) = mass × velocity = mv

• SI unit: kg m/s (or N s)
• It is a vector quantity, so it has both magnitude and direction.

3. Check each option

• A. Acceleration: This is the rate of change of velocity (a = Δv/t). It does not involve mass, so it is not the quantity of motion.
• B. Displacement: This is the distance moved in a particular direction. It describes position change, not the quantity of motion.
• C. Momentum: This is mass × velocity, which is exactly the "quantity of motion."
• D. Velocity: This is the rate of change of displacement. It has no mass component, so it is only part of what makes up momentum.

4. Answer The correct option is C. momentum (spelled "mometum" in the question, which is just a typo).

5. Exam tip Link the phrases to the quantities:

• "Quantity of motion" → momentum (mv)
• "Rate of change of momentum" → force
• "Rate of change of velocity" → acceleration

If you see "quantity of motion," think of mass and velocity together. Keep going, you're doing well!