The statement given below signifies which of the law/principle given in the options. 'An object remains in a state of rest or of uniform motion in a straight line unless compelled to change that state by an applied force.'
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1: Newton's First Law of Motion.
Explanation:
The statement provided in the question is the precise definition of the First Law of Motion, as propounded by Sir Isaac Newton. It is also known as the Law of Inertia.
• Essence of the Law: An object maintains its current state (whether at rest or in a state of uniform motion) unless acted upon by an unbalanced external force.
• Inertia: This is a property of an object by virtue of which it resists any change in its state. Heavier objects possess greater inertia because they have a larger mass.
Newton's Other Laws of Motion (For Revision):
Questions regarding these three laws are frequently asked in competitive examinations:
Law Name Key Formula/Principle
First Law Law of Inertia Defines force.
Second Law Law of Momentum Provides the formula for measuring force: F = ma
Third Law Law of Action and Reaction For every action, there is an equal and opposite reaction.
Examples of the First Law in Daily Life:
1. Sudden start of a bus: When a stationary bus suddenly starts moving, the passengers lean backward (due to inertia of rest).
2. Shaking a rug or carpet: When a carpet is beaten with a stick, the dust particles remain in their original position due to inertia and separate from the carpet.
3. A fast-moving ball: A moving ball does not stop until it is halted by friction or by a player.
Important Questions for Upcoming Examinations:
Question: From which of Newton's laws is the definition of Force derived?
Answer: From the First Law.
Question: What is the measure of Inertia?
Answer: The mass of an object.
Question: What is 'Bernoulli's Principle' (Option 4) related to? Answer: This relates to the flow and pressure of fluids (liquids and gases).