DEMONSTRATION CLASS

1. 7E’S SCIENCE LESSON PLAN

2. Dr Muttu Vemula
Assistant Professor
Department of Education
Mizoram University (A Central
University)

3. Name:
Date : ___/___/____
Class : IX
Section : A
Period : 2nd Period
Duration : 40 Minutes
Subject : Physics
Topic : Work and Energy

4. GENERAL OBJECTIVES:
1. Students will be able to acquire scientific knowledge
2. Students will be able to apply the scientific facts in life situations
3. Students will be able to develop the capacity to solve problems
SPECIFIC OBJECTIVES:
1. Students will be able to define work and energy
2. Students will be able to know relationship between work and energy.
3. Students will be able to explain kinetic and potential energy
4. Students will be able to apply the concept of force in daily life situations.
5. Students will be able to derive kinetic and potential energy.
6. Students will be able to solve the numerical related to kinetic and potential
energy.
7. Students will be able to analyze the law of conservation of energy

5. Method: Inductive and deductive Method
T.L.M/Teaching Aids: Toy Car, Ball, Book, Slinky, Table, Chair and
Stone
Previous Knowledge: Equations of Motion, Newton’s Second Law
of Motion
Introduction: The teacher introduces the lesson by asking questions
from day to day life. For doing running, jumping and walking etc
what does a living organism require? From where does the energy
come from?... Can we say that by pushing a table, by pulling a chair
and lifting a book work is been done?
Statement of the Topic: The teacher announces the topic of
discussion as work and energy

6. PRESENTATION
Teaching Points Teacher’s Activity Students’ Activity Blak Board/TLM/Diagram
Work/Elicit

7. ELICIT
Suma is swimming in a pond.
• A donkey is carrying a load on its back.
• A wind-mill is lifting water from a well.
• A green plant is carrying out photosynthesis.
• An engine is pulling a train.
• Food grains are getting dried in the sun.
• A sailboat is moving due to wind energy.

8. Answer
• Suma is swimming in a pond.
Suma is doing work as she is able to move herself by applying force with
the movement of her arms and legs in the water.
• A donkey is carrying a load on its back.
Donkey is not doing any work (in the sense of physics) as the weight he is
carrying (the direction of force) and displacement are perpendicular to each
other.
• A wind-mill is lifting water from a well.
Wind mill is lifting water from a well and doing work against the gravity.
• A green plant is carrying out photosynthesis.
No force and displacement are present here, so work done is zero.
•

9. An engine is pulling a train.
During the pulling a train, engine does the work against the friction,
present
between the railway track and wheels.
• Food grains are getting dried in the sun.
During the drying the grains, there is no force as well as
displacement is
present. So, no work is done.
• A sailboat is moving due to wind energy.
Work is done by the wind as it moves the sailboat towards the
direction of
the force (force of blowing air).

11. WORK/ENGAGE

13. Work
• What does WORK mean to you?
• Are you doing WORK when…
– Lifting weights?
– Walking with a big bag of grocery in your hand?
– Completing your homework assignment?
– Writing an essay?

14. Physics concept of WORK
• WORK is done only when a constant force
applied on an object, causes the object to move in
the same direction as the force applied.

15. • What IS considered as work done in Physics:
– You push a heavy shopping trolley for 10 m
– You lift your school bags upwards by 1 m
• What is NOT considered as work done:
– You push against a wall
– Jumping continuously on the same spot
– Holding a chair and walking around the classroom

16. Energy
Which is the is the biggest natural source of energy to us----------------------
Examples: 1. when a fast moving cricket ball hits a stationary wicket, the
wicket is thrown away.
Example-2 you must have seen raised hammer falls on a nail placed on a piece
of wood, it drives the nail into the wood
Example:3We have also observed children winding a toy (such as a toy car) and
when the toy is placed on the floor, it starts moving.
Example-4 When a balloon is filled with air and we press it we notice a change
in its shape. As long as we press it gently, it can come back to its original shape
when the force is withdrawn. However, if we press the balloon hard, it can even
explode producing a blasting sound

17. In all these examples, the objects acquire, through
different means, the capability of doing work.
An object having a capability to do work is said to
possess energy. The object which does the work loses
energy and the object on which the work is done gains
energy

18. What are the different forms of energy do you know

19. Explore
WORK can be calculated by:
Work done = Constant
force (N) x Distance moved in the direction of force (m)
W = F x s
Units: [J][N] [m]
SI Unit for Work is JOULE (J)

23. Explain

24. More Examples of WORK
•You are helping to push your mother’s heavy shopping cart with a force of
50 N for 200 m. What is amount of work done?
Work done, W = F x s
= 50 x 200
= 10,000 J
or
10 kJ (kilo-Joules)

25. Question :
A force of 7 N acts on an object. The displacement is,
say 8 m, in the direction of the force. Let us take it
that the force acts on the object through the
displacement. What is the work done in this
case?

26. Answer :
When a force F acts on an object to displace it through a distance S in
its direction, then the work
done W on the body by the force is given by:
Work done = Force × Displacement
W = F × S
Where,
F = 7 N
S = 8 m
Therefore, work done, W = 7 × 8
= 56 Nm
= 56 J

27. Energy

31. Forms of Energy

40. • Find the KE of an empty van of mass 1000kg moving at 2m/s.
• Find the KE of van when it is loaded with goods to give a total
mass of 2000kg, and moving at 2m/s.

41. KE of van at 2m/s = ½ x 1000 x (2)2
= 2000 J = 2 kJ
KE of van at 2m/s = ½ x 2000 x (2)2
= 4000 J = 4 kJ

42. Evaluation

46. Extends
1. What is the relationship of work and energy?
2. An object thrown at a certain angle to the ground
moves in a curved path and falls back to the ground.
The initial and the final points of the path of the
object lie on the same horizontal line. What is the
work done by the force of gravity on the object?
3. A battery lights a bulb. Describe the energy
changes involved in the process.

47. Assignment
1.Explain about work
2.what are the forms of Energy
Look at the activities listed below. Reason out
whether or not work is done in the light of your
understanding of the term ‘work’.
• Suma is swimming in a pond.
• A donkey is carrying a load on its back.
• A wind-mill is lifting water from a well.
• A green plant is carrying out photosynthesis.
• An engine is pulling a train.
• Food grains are getting dried in the sun.