NCERT Solutions for Class 9 Science Chapter 9 : Force And Laws Of Motion

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The NCERT Solutions for Class 9 Science Chapter 9 Force And Laws Of Motion are provided in this article below. Some of the important concepts of Class 9 Science Chapter 9 Force and Laws of Motion are:

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NCERT Solutions for Class 9 Science Chapter 9

NCERT Solutions for Class 9 Science chapter 9

Important Topics for Class 9 Science Chapter 9 Force and Laws of Motion

Force can be used to change the magnitude of velocity of an object (that is, to make the object move faster or slower) or to change its direction of motion. It is an external agent that can potentially change the state of rest or motion of any body.

Balanced and Unbalanced Forces

Balanced force can be expressed as two magnitudes, typically equally, with opposite directional forces acting on a body. Unbalanced forces occurs when two forces are seen to act in opposite directions on a body and aren’t equal in either magnitude or in size.

Example of Balanced Force: When a vehicle is pushed with equal force from either sides, it will keep remaining at a resting state.
Example of Unbalanced Force: The movement of a seesaw.

Laws of Motion

Newton’s laws of motion are the fundamental building blocks of classical mechanics. Motion can be defined as the change in position of a body on basis of its surroundings in a respective time interval.

Example: What are the Newton’s laws of Motion?

Solution: Newton’s laws of Motion are:

First Law of Motion claims that a body will not change its state of rest or motion, unless an external force acts on it.
Second Law of Motion claims that the greater the mass of the body, the greater will the required force in order to accelerate it.
The Third Law of Motion claims that for every action, there is an equal and opposite reaction.

Conservation Laws

The laws of conservation include but are not limited to conservation of mass, energy, linear momentum and angular momentum. Conservation laws are known to deal with the fundamental forces of nature.

Example: Give two primary examples of conservation of energy.

Solution: The two primary examples of conservation of energy are:

Electrical energy being converted into sound energy.
Mechanical energy being converted into electrical energy.

Also Read:

Chapter Related Links
Law of Inertia	Unit of Moment of Inertia	Effects of Force
First Law of Motion	Second Law of Motion	Third Law of Motion
Difference Between Force and Momentum	Difference Between Momentum and Inertia	Linear Momentum Formula
Mass and Momentum	Moment Of Force	Interaction of Forces & Effects of Force Interaction
Inertia	Unit of Mass

Read More:

Important Science Study Guides
Named Reactions	Physics Constants	Difference between in biology
Difference between in chemistry	Difference between in physics	Periodic Table

CBSE X Related Questions

1.
Assertion : Bacteria produced as a result of asexual reproduction would be similar. Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
View Solution
2.
Which of the following group is not 'biodegradable'?
- Vegetable peels, dead leaves, paper
- Cow dung, leather bag, water
- Polythene bag, rubber band, ball pen
- Paper, fruits, bones
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3.
Which of the following will not undergo addition reaction?
- C$_4$H$_8$
- C$_2$H$_2$
- C$_3$H$_8$
- C$_2$H$_4$
View Solution
4.
The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:
- tomato, curd, ant-sting
- tomato, orange, nettle-sting
- orange, milk, ant-sting
- orange, sour milk, nettle-sting
View Solution
5.
The reasons for excessive generation of wastes are:
(i) Use and throw policy.
(ii) Increased availability of packaged food.
(iii) Increased construction wastes.
(iv) Non-sorting of dry and wet wastes
- (i), (iii) and (iv)
- (i), (ii) and (iii)
- (i), (ii), (iii) and (iv)
- (ii), (iii) and (iv)
View Solution
6.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
View Solution