Newton’s First Law of Motion - Complete Notes
Statement
Newton’s First Law of Motion states that: 'An object remains at rest, or continues to move in a
straight line with uniform speed, unless an external force is applied on it.' This law is also called the
Law of Inertia.
Key Points
1. Rest and Motion: A body at rest stays at rest, and a body in motion continues moving unless
acted upon by an external force.
2. Inertia: The tendency of a body to resist change. Types: Inertia of Rest, Inertia of Motion, Inertia
of Direction.
3. Force: Required to change the state of motion.
Examples in Daily Life
• A book on a table stays at rest until pushed.
• Passengers fall forward when a bus stops suddenly.
• Passengers lean sideways when a car takes a turn.
Importance
• Explains why seat belts are necessary.
• Basis of mechanics.
• Explains balanced and unbalanced forces.
Exercises
A. Fill in the blanks
1 Newton’s First Law of Motion is also called the law of _______.
2 The natural tendency of a body to resist change in its state of motion is called _______.
3 Passengers fall forward in a suddenly stopped bus due to inertia of _______.
4 Force is required to change the _______ of a body.
5 A body at rest will remain at _______ until an external force acts on it.
B. True or False
1 A moving object will stop on its own without any external force.
2 Inertia is the tendency to oppose change.
3 Newton’s First Law explains why a football will not move until it is kicked.
4 Passengers lean forward when a bus starts suddenly due to inertia of rest.
5 Force is necessary to maintain motion of an object.
Statement
Newton’s First Law of Motion states that: 'An object remains at rest, or continues to move in a
straight line with uniform speed, unless an external force is applied on it.' This law is also called the
Law of Inertia.
Key Points
1. Rest and Motion: A body at rest stays at rest, and a body in motion continues moving unless
acted upon by an external force.
2. Inertia: The tendency of a body to resist change. Types: Inertia of Rest, Inertia of Motion, Inertia
of Direction.
3. Force: Required to change the state of motion.
Examples in Daily Life
• A book on a table stays at rest until pushed.
• Passengers fall forward when a bus stops suddenly.
• Passengers lean sideways when a car takes a turn.
Importance
• Explains why seat belts are necessary.
• Basis of mechanics.
• Explains balanced and unbalanced forces.
Exercises
A. Fill in the blanks
1 Newton’s First Law of Motion is also called the law of _______.
2 The natural tendency of a body to resist change in its state of motion is called _______.
3 Passengers fall forward in a suddenly stopped bus due to inertia of _______.
4 Force is required to change the _______ of a body.
5 A body at rest will remain at _______ until an external force acts on it.
B. True or False
1 A moving object will stop on its own without any external force.
2 Inertia is the tendency to oppose change.
3 Newton’s First Law explains why a football will not move until it is kicked.
4 Passengers lean forward when a bus starts suddenly due to inertia of rest.
5 Force is necessary to maintain motion of an object.
