The tendency of a body to remain at rest when a force is applied to it is called.

1. Analyze the question

The question asks for the specific term used in physics to describe the resistance an object offers to any change in its state of rest or uniform motion.

2. Explain the concept

This concept is rooted in Newton’s First Law of Motion, often called the Law of Inertia.

• Inertia is the inherent property of matter that causes it to resist changes in its velocity. If an object is stationary, it wants to stay stationary; if it is moving, it wants to keep moving in a straight line at a constant speed.
• Impulse is the product of force and time ($F \times t$), which relates to a change in momentum.
• Momentum is the product of mass and velocity ($p = mv$).
• Friction is a resistive force that acts between two surfaces in contact, opposing motion.

3. Show the solution

• The question specifically mentions the "tendency of a body to remain at rest."
• According to the definition of Newton's First Law, a body will maintain its state of rest or uniform motion unless acted upon by an external force.
• The measure of this resistance to change is defined as Inertia.
• Therefore, when a force is applied to a body at rest, the body's "stubbornness" to stay at rest is its inertia.

4. Identify the answer

Comparing our explanation to the given options:

• A. Impulse (Incorrect)
• B. Momentum (Incorrect)
• C. Inertia (Correct)
• D. Friction (Incorrect)

5. Exam Tip

Think of Inertia as "laziness." A heavy object (large mass) has more "laziness" (greater inertia) than a light object. This is why it is much harder to push a stationary truck than it is to push a stationary bicycle!