NCERT Solutions for Class 9 Science Chapter 11: Work and Energy

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The NCERT Solutions for Class 9 Science Chapter 11 Work and Energy have been given in this article. Some of the important topics of Class 9 Science Chapter 11 Work And Energy include:

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NCERT Solutions for Class 9 Science Chapter 11

Important Topics for Class 9 Science Chapter 11 Work and Energy

Work is closely related to energy. The work–energy principle states that an increase in the kinetic energy of a rigid body is caused by an equal amount of positive work done on the body by the resultant force acting on that body.

Work Energy Theorem and its Applications

Work can be defined as the transfer of energy into an object in order to cause it to move or displace. Energy can be expressed as the capacity to do work.

Example: State the Work-Energy theorem in brief.

Solution: The Work-Energy theorem expresses the following formula:
W = ΔKE = ½ mv2f − ½ mv2i

Here,

vi = Particle speed before the application of force
vf = Particle speed after the application of force
m = Particle’s mass

Kinetic Energy

Kinetic Energy can be defined as the energy generated due to motion by an object. It can also be expressed as the energy that helps accelerate a body of rest to motion.

Example: What are the five major types of Kinetic Energy?

Solution: The five major types of Kinetic Energy are:

Radiant Energy
Thermal Energy
Sound Energy
Electrical Energy
Mechanical Energy

Thermal Energy

Thermal energy refers to the energy that a body is known to generate during when its atoms or molecules displace.

Example: What are two important points of Thermal Energy?

Solution: The two major points of Thermal Energy include:

The temperature of any given substance is found to hold a direct relationship with its thermal energy.
When the amount of heat present is in or out of the given object, then the thermal energy is seen to alter.

Also Check:

Unit Related Links
Conservation of Energy Formula	Types of Energy	Kinetic Energy Formula
Potential Energy	Power	Law of Conservation of Energy
Conservation Of Mechanical Energy	Gravitational Potential Energy	Kinetic and Potential Energy Difference
Potential Energy of Spring	Conservation Laws in Physics	Lenz Law and Conservation of Energy

Also Read:

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

CBSE X Related Questions

1.
Which of the following set of compounds does not belong to same homologous series?
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- C$_3$H$_8$ and C$_5$H$_{12}$
- C$_4$H$_8$ and C$_5$H$_{12}$
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State two differences between pollination and fertilization.
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3.
The pattern of magnetic field due to a current carrying wire depends upon the shape made by that wire. Justify.
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Given below is a pyramid showing various trophic levels in an ecosystem:
(a) From the organisms listed below, identify which one is to be placed at which trophic level:
Deer, Grass, Lion, Snake, Rabbit
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(c) Why is the base of the pyramid broad?
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5.
Yeast multiplies by which of the following methods?
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6.
Assertion (A): Reflex actions do not involve thinking.
Reason (R): Most reflex actions are controlled by the spinal cord.
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