📚 Topic Summary
Inertia is an object's resistance to changes in its state of motion. If an object is at rest, it tends to stay at rest. If an object is moving, it tends to keep moving with the same velocity (speed and direction). Mass is a measure of inertia; the more massive an object is, the greater its inertia. This concept is directly related to Newton's First Law of Motion.
🧠 Part A: Vocabulary
Match the terms with their definitions:
| Term |
Definition |
| 1. Inertia |
A. A measure of how difficult it is to change an object's velocity. |
| 2. Mass |
B. The tendency of an object to resist changes in its state of motion. |
| 3. Newton's First Law |
C. An object at rest stays at rest, and an object in motion stays in motion with the same speed and direction unless acted upon by a force. |
| 4. Force |
D. An interaction that, when unopposed, will change the motion of an object. |
| 5. Equilibrium |
E. A state where the net force acting on an object is zero, resulting in no change in motion. |
Match the term to the correct definition:
1 - B, 2 - A, 3 - C, 4 - D, 5 - E
✍️ Part B: Fill in the Blanks
__________ is the property of an object to resist changes in its motion. The more __________ an object has, the greater its inertia. According to __________ Law, an object will remain at rest or in uniform motion in a straight line unless acted upon by an external __________. This law is also known as the Law of __________.
Answers: Inertia, mass, Newton's First, force, Inertia
🤔 Part C: Critical Thinking
Imagine you are in a car moving at a constant velocity. The driver suddenly slams on the brakes. Explain what happens to you in terms of inertia and why.
Answer: When the car suddenly brakes, your body tends to continue moving forward due to inertia. Your body resists the change in motion, and you will feel like you are being thrown forward until a force, such as the seatbelt, stops you.