Energy
Energy
Energy
Plan in Science 9
I. Lesson Objectives
At the end of the lesson, 100% of the students with at least 80% level of proficiency will be able to:
A. Define Energy,
C. Solve word problems using Potential Energy and Kinetic Energy Equation.
Values Integration
To inculcate deeper sense of appreciation on energy around us. As what Rachel Burmingham
quoted, “The energy we put out, is the energy we get back.”
A. Topic: Energy
B. Reference:
pg no. 281-282
tmurphy.physics.uscd.edu
C. Materials:
Blackboard
Chalks
Erasers
D. Concept:
Forms of Energy
Kinetic Energy - is the energy that is in motion. The Kinetic Energy Equation
is KE = mv2/2.
E. Skills:
Defining terms.
1
Differentiating forms of energy.
a. Opening Prayer
Before we start, let us all stand and ask for the
guidance of our Almighty God.
please lead the prayer. Let us bow our heads and pray.
b. Greetings
Good morning class! Good morning ma’am!
c. Checking of Attendance
, is there any absent for today? Ma’am I am glad to tell you that nobody is absent
for today.
d. Checking of Assignments
(The teacher will show the answers on the (The students will check their assignment)
Very good!
2
B. Motivation
3
(The students start to guess the answer and later
raise their illustration board.)
C. Lesson Proper
The last slide shows us pictures of energy, will you Ma’am, energy is the ability to do work.
define energy?
Very good!
And energy has two major forms, anyone who Ma’am, the two major forms of energy are
knows what are they? Potential Energy and Kinetic Energy.
Absolutely!
Ma’am, the second form of energy is Kinetic
How about the second form of energy? Energy!
Excellent!
5
Science? Yes ma’am. The language of Science is
Mathematics.
PEgrav = mgh
where:
PEgrav = gravitaional potential energy
m = mass of an object
g = acceleration due to gravity
H = height of an object
Excellent!
mv2
KE =
2
where:
KE = kinetic energy
m = mass of an object
v = velocity of an object
6
Let’s have an example.
Will you please read the problem?
A baseball that weighs 1.38 kg is thrown so that it
attains a velocity of 18 m/sec. What is the kinetic
Good! Can you identify the mass?
energy?
Correct! How about the velocity?
Ma’am, the mass of the object is 1.38kg
Awesome! Who wants to solve the problem?
Solution:
PE = (mass)(gravity)(height)
= (10 kg)(9.8 m/s2)(2 m)
= 196 kg • m2/s2
= 196 J
2. Given:
m = 14kg
v = 3m/s
Find:
KE=?
Solution:
KE = mv2 / 2
= (14 kg)(3.0 m/s)2 / 2
= 2,205 kg • m2/s2
= 2,205 J
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Very good class!
E. Valuing
energy?
None ma’am!
IV. Evaluation
Please get 1/2 sheet of paper.
I. Choose the best answer.
1. Energy is defined as the ability to do ?
a. power b. work c. momentum
2. What form of energy is defined as energy
in motion?
a. kinetic b. potential c. mechanical
3. What form of energy is defined as energy
at rest?
a. kinetic b. potential c. mechanical
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4. Which variable belongs to Potential Energy
Equation?
a. acceleration b. speed c. height
5. Kinetic Energy Equation has these variables, Answers
except ? I.
a. time b. mass c. velocity 1. b
2. a
3. b
II. Problem Solving (5pts) 4. c
A girl on a motorbike passes by at a speed of 5. a
15m/sec. Her mass is 40 kg. What is her kinetic
energy?
II.
V. Assignment
Answer the following. Given:
1. A 15kg flower pot was placed on a window sill m = 40 kg
15 meters above the ground. How much potential v = 15 m/s
energy does the flower pot contain?
2. Define work. Find:
KE = ?
Solution:
KE = mv2 / 2
KE = (40 kg)(15 m/s)2 / 2
KE = (40 kg)(225 m2/s2) / 2
KE = 4,500 kg•m2/s2
KE = 4,500 J