Understand the concept of work,
energy and power.
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2
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Define work, energy and power.
Calculate the form of energy by using formula
Kinetic Energy and Potential Energy.
State the principal of conservation energy.
Describe conversion from one form to another
form
Apply the concept and formula of work, energy
and power in solving the related problems.
Calculate the efficiency of mechanical system
efficiency
Q1: How many steps of batu cave stair?
Q2: What is the height of the stair?
answer:
Q3: How to measure our work or energy
when climb a stair?
Q4: How would increase your power
rating when climbing upstairs?
Outcomes:
Define work,
energy and
power
What does WORK mean to you?
Are you doing work when….
Lifting a weights?
Walking with a bag grocery in your hand?
Completing your homework assignment?
Writing essay?
https://www.youtube.com/watch?v=pDK2p1QbPKQ
Outcomes:
Define work,
energy and
power
WORK is defined when a force is applied through a
displacement on a system
Displacement
Outcomes:
Define work,
energy and
power
 A force that acts
opposite to the
direction of motion of
an object does
negative work
 No work (W=0) will be
done when the
displacement equals
zero or when the force
is perpendicular to the
displacement.
Outcomes:
Define work,
energy and
power
WORK is defined as product of the force and displacement
of an object in the direction of force.
Read the following four statements and determine whether or not
they represent examples of work.
1. A teacher applies a force to a wall and becomes exhausted.
2. A book falls off a table and free falls to the ground.
3. A waiter carries a tray full of meals above his head by one arm
straight across the room at constant speed. (Careful! This is a
very difficult question that will be discussed in more
detail later.)
4. A rocket accelerates through space.
Outcomes:
Define work,
energy and
power
 Formula of work is
W = FΔd
 Formula of work when force and displacement are at an angle
W = FΔd (cos Ө)
Quantity
Variable
Unit
Work
W
Joule (J)
Force
F
Newton (N)
Displacement
Δd
Meter (m)
Angle
Ө
Degree (º)
Outcomes:
Define work,
energy and
power
Check Point:
Apply the work equation to determine the amount of work done by the
applied force in each of the three situations described below.
Outcomes:
Define work,
energy and
power
Closing Task:
I will differentiate between my
definition of work and the Physics
definition of work and state how
work, power and energy are related
Outcomes:
Define work,
energy and
power
Power is defined as ability to do work.
SI Unit : Watt (W)
Formula:
Work
Power 
time
W
P
t
Power 
Joule
second
Force  displacement
time
Power  Force  velocity
The Power of body…..
Strong and Fast…… (Big Force and small times..)
Outcomes:
Define work,
energy and
power
Energy is defined as CAPACITY TO DO WORK.
SI Unit : Joule (J)
Many form.
Common one:
 Kinetic
 Potential
 Electric
 Chemical
 Solar
 Nuclear