Question

The total motion possessed by a body is called: ____.

• A. impulsive force
• B. mass
• C. weight
• D. momentum

Hint:

Think of momentum as "mass in motion." If an object is moving, it has momentum. To change that momentum, you must apply an Impulse (Force $\times$ Time).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Motion is not just about how fast an object is moving (velocity); it also depends on how much "stuff" is moving. A heavy truck moving at 10 mph has more "motion" than a bicycle moving at the same speed.

Step 2: Key Formula or Approach:
The quantity of motion is mathematically defined as: \[ p = m \times v \] where $m$ is mass and $v$ is velocity.

Step 3: Detailed Explanation:
Momentum is the term used in physics to describe the "total motion" or "quantity of motion" possessed by an object. It is a vector quantity that depends on both the mass and the velocity of the body. An object at rest has zero momentum. Because it includes both mass and speed, momentum tells us how difficult it will be to stop the object; a high-momentum object requires a significant force applied over time to be brought to a halt.

Step 4: Final Answer:
The total motion possessed by a body is called momentum.

Answer 2

The question asks which term means the total motion possessed by a body. A useful test is to check what happens to each quantity when the body is completely at rest, since a body at rest has zero motion, whatever quantity truly represents motion should also become zero in that case.

1. Impulsive force: A force is not a property of the body's own state of motion at all, it is something external being applied to the body over time. It doesn't represent the motion the body possesses.
2. Mass: A body at rest still has exactly the same mass as it does while moving, mass doesn't change or vanish just because the object stops moving. Since it stays constant regardless of motion, it cannot represent the motion possessed by the body.
3. Weight: Similarly, a body sitting still on a table still has its full weight acting on it, weight has nothing to do with whether the body is moving or not.
4. Momentum: Momentum is defined as \( p = mv \). If the body is at rest, \( v = 0 \), so its momentum is exactly zero. As the body moves faster, its momentum grows in proportion to both its mass and its speed, capturing exactly the idea of total motion, heavier and faster bodies possess more of it.

Only momentum vanishes precisely when the body has no motion at all, and grows with both mass and speed otherwise, matching the description of total motion possessed.

Therefore, the correct answer is momentum.