Uploaded by sharin15marato

a-detailed-lesson-plan-in-science-for-grade-9-students (1)

advertisement
A Detailed Lesson Plan
In Science for Grade 9 Students
Prepared by: Rolalen Joyce C. Paiton
I.
Objective
General Objective: Describe the Uniformly Accelerated Motion (UAM)
qualitatively and quantitatively.
Specific Objective: Solve problems related to motion with uniform
acceleration in horizontal dimension.
II.
Subject Matter
A. Uniformly Accelerated Motion
B. References:
Science Learner’s Module
Science Teacher’s Module
University Physics by Young and Freedman
C. Instructional Materials:
Pictures, Visual Aids, PowerPoint, Videos
D. Value Integration: Honesty
E. Science Concepts:
The simplest kind of accelerated motion is straight-line motion with
constant acceleration. In this case, the velocity changes at the same rate
throughout the motion. Uniformly Accelerated Motion occurs when a
velocity increases by exactly the same amount during each time interval.
Skills processed: Observing, Determining
III.
Procedure
Teacher’s Activity
Students’ Activity
A. Preliminary Activities
“Good morning class! How was
“Good morning ma’am!”
your weekend?”
“As a part of my classroom
management I want to assign
an officer of the day. It would
be alphabetical, so today the
officer of the day is Brendon
and for tomorrow the OD is
Jhon Hardy. The OD is in
charge for checking the
“Okay ma’am.”
attendance, he/she will be the
one to lead the prayer and setup theTV. Also I’ll be giving
points to those students who
will participate in the class
discussion.”
(students pray)
“Please stand everyone for the
prayer and Brendon as the
officers of the day please lead
“None ma’am.”
the prayer.”
(students perform an energizer
“Is anyone absent today?”
activity)
“It’s time for an energizer.”
“We discussed about Uniformly
Accelerated Motion.”
B. Review Lesson
“What have we discussed last
meeting”?
“Uniformly
Accelerated
Motion.is
simply
motion
constant
a
with
“Very good.”
acceleration.
“What is Uniformly Accelerated
velocity changes at the same rate
Motion?”
throughout the motion.”
In
“Very good. You really listened
to our discussion last meeting.”
C. Lesson Proper
(students answer)
1. Motivation
“If you want to determine
how far a passing vehicle
would travel in a given
amount of time, how will you
do it?”
“The best way to solve a
problem
is
usually
this
case
the
determined
by
the
information that is available
to you.”
2. Presentation
“Our
topic
Equations
for
for
today
is
Uniformly
Accelerated Motion”
(Presentation of objectives)
Objectives:
The learners should be able
to:
•
Solve problems related
to
motion
with
acceleration
in
uniform
horizontal
(students read the objectives)
dimension.
“Please read the objective.”
“Thank you.”
3. Discussion
“To
be
able
to
solve
problems related to motion
with uniform acceleration, in
which
the
velocity
may
change but the acceleration
is constant, we need to
derive algebraic equations
that describe this type of
motion.”
𝑣𝑓 − 𝑣𝑖
π›₯𝑣
𝑣𝐴𝑣𝑒 =
2
=
2
“What is the formula for
average velocity?”
“Thank you.”
“How about the formula for
average acceleration?”
π‘Žπ΄π‘£π‘’ =
π›₯𝑣
π›₯𝑑
=
𝑣𝑓 − 𝑣𝑖
π›₯𝑑
“Very good.”
“Consider
the
defining
equation for acceleration:
𝑣𝑓 − 𝑣𝑖
π‘Žπ΄π‘£π‘’ =
π›₯𝑑
“If
we
rearrange
this
equation to solve for final
velocity 𝑣𝑓, we get Equation
1:
𝑣𝑓 = 𝑣𝑖 + π‘Žπ›₯𝑑 (Equation 1)”
“You may use Equation 1 in
problems that do not directly
involve displacement.”
Substitute Equation 1 to
𝑣𝑖 + 𝑣𝑓
𝑣𝐴𝑣𝑒 =
2
1
𝑣𝐴𝑣𝑒 = (𝑣𝑖 + 𝑣𝑓)
2
1
𝑣𝐴𝑣𝑒 = (𝑣𝑖 + 𝑣𝑖 + π‘Žπ›₯𝑑)
2
1
𝑣𝐴𝑣𝑒 = (2𝑣𝑖 + π‘Žπ›₯𝑑)
2
1
𝑣𝐴𝑣𝑒 = (𝑣𝑖 + π‘Žπ›₯𝑑)
2
π›₯π‘₯
Then substitute to 𝑣𝐴𝑣𝑒 = 𝑑
1
We get π›₯π‘₯
and
=
𝑣
𝑖 + π‘Žπ›₯𝑑
𝑑
2
multiply it by t.
π›₯π‘₯=𝑣 𝑑+1 π‘Žπ›₯𝑑2 (Equation 2)
𝑖
2
“This is Equation 2, which
allows you to determine the
displacement of an object
moving
with
uniform
acceleration given a value
for acceleration rather than
a final velocity.”
𝑣𝑓−𝑣𝑖
π›₯𝑑=
π‘Ž
,𝑣
𝐴𝑣𝑒
=
𝑣𝑓+𝑣𝑖
2
π›₯π‘₯=vt
π›₯π‘₯=(
𝑣𝑓+𝑣𝑖
𝑣𝑓−𝑣𝑖
2
π‘Ž
)(
π›₯π‘₯ = (
𝑣𝑓2
3)
)
𝑣𝑓2 − 𝑣𝑖2
)
2π‘Ž
2π‘Žπ›₯π‘₯ = 𝑣𝑓2 − 𝑣𝑖2
= 𝑣𝑖2 + 2π‘Žπ›₯π‘₯(Equation
𝑣𝐴𝑣𝑒 =
𝑣𝑖+𝑣𝑓
2
, 𝑣𝐴𝑣𝑒 =
𝑣𝑖 + 𝑣𝑓
2
π›₯𝑑(
π›₯π‘₯ = (
π›₯π‘₯
𝑑
𝑣𝑖+𝑣𝑓
2
=
=
π›₯π‘₯
𝑑
,
π›₯π‘₯
π›₯𝑑
𝑣𝑖 + 𝑣𝑓
2
)
)π›₯𝑑 (Equation 4)
“We can use Equation 4 to
determine the displacement
of
an
object
undergoing
that
is
uniform
acceleration.”
“Let us solve some sample
problems. “
1. A sports car approaches
Given:
a highway on-ramp at a
vi= 20.0 m/s East ;
velocity of 20.0 m/s East. If
aAve =3.2 m/s2 East;
the car accelerates at a rate
Δt= 5s
of 3.2 m/s2 East for 5.0 s,
Required:
what is the displacement of
Δx
the car?
Analysis: Our first task is
to determine which of the
four
equations
of
accelerated motion to use.
Usually, we can solve a
problem using only one of
the four equations. We
simply
identify
which
equation contains all the
variables for which we
have given values and the
unknown variable that we
are asked to calculate. In
the table, we see that
Equation 2 has all the
given variables and will
allow us to solve for the
unknown variable.
Solution:
π›₯π‘₯=𝑣 π›₯𝑑+1 π‘Žπ›₯𝑑2
𝑖
2
π‘š
π›₯π‘₯=(20 )(5𝑠)+
𝑠
1 (3.2
2
π‘š
)(5𝑠)2
𝑠2
π›₯π‘₯=100m+40m
π›₯π‘₯=140m East
Statement: During the 5.0
s time interval, the car is
displaced 140 m East.
2. A sailboat accelerates
uniformly from 6.0 m/s North
to 8.0 m/s North at a rate of
0.50
m/s2
distance
North.
does
the
What
boat
travel?
“What
are
the
π‘š
π‘š
𝑠
𝑠
given “Given: vi= 6 , vf= 6 and
quantities in the problem?”
“What is required in this
problem?”
π‘š
aAve= 0.50
𝑠2
“Distance”
“Base on the table which
equation will allow us to
solve for the unknown
variable. “
First, we rearrange the
equation
to solve for Δx.”
Solution:
𝑣𝑓2 = 𝑣𝑖2 + 2π‘Žπ›₯π‘₯
𝑣𝑓2 − 𝑣𝑖2 = 2π‘Žπ›₯π‘₯
𝑣𝑓2 − 𝑣𝑖2
π›₯π‘₯ =
2π‘Ž
π‘š
π‘š
(8 )2 − (6 )2
𝑠
𝑠
π›₯π‘₯ =
π‘š
2(0.50 𝑠2)
π‘š 2
π‘š
(64 ) − (36 )2
𝑠
𝑠
π›₯π‘₯ =
π‘š
1 𝑠2
π›₯π‘₯ = 28π‘š
Statement: The boat
travels a distance of 28 m.
3. A dart is thrown at a
target that is supported by a
For a:
Given: vi= 350
π‘š
πΈπ‘Žπ‘ π‘‘ ,
𝑠
π‘š
πΈπ‘Žπ‘ π‘‘, Δt=0.0050s
wooden backstop. It strikes
vi= 0
the backstop with an initial
Required: aAve
velocity of 350 m/s [E]. The
“We may use the defining
dart comes to rest in 0.0050
equation for acceleration:
s.
(a) What is the acceleration
𝑠
π‘Žπ΄π‘£π‘’ =
𝑣𝑓−𝑣𝑖
π›₯𝑑
”
of the dart?
(b) How far does the dart
penetrate into the backstop?
Solution:
𝑣𝑓 − 𝑣𝑖
π‘Žπ΄π‘£π‘’ =
π›₯𝑑
π‘š
π‘š
0 − 350
𝑠
π‘Žπ΄π‘£π‘’ = 𝑠
0.0050𝑠
π‘š
π‘Žπ΄π‘£π‘’ = −70000 2
𝑠
π‘š
π‘Žπ΄π‘£π‘’ = 70000 2 , π‘Šπ‘’π‘ π‘‘
𝑠
“To solve (b), we have
sufficient
information
to
solve the problem using
any
equation
displacement
with
in
it.
Generally speaking, in a
two-part problem like this,
it is a good idea to try to
find an equation that uses
only
given
information.
Then, if we have made an
error in calculating the first
part
(acceleration),
our
next calculation would be
unaffected by the error.
Therefore,
we
will
use
Equation 4 to solve (b),
since it can be solved
using
only
given
information.
Given: vi= 350
π‘š
πΈπ‘Žπ‘ π‘‘ ,
𝑠
vi= 0
π‘š
πΈπ‘Žπ‘ π‘‘, Δt=0.0050s
𝑠
Required: Δd
Solution:
𝑣𝑖 + 𝑣𝑓
π›₯π‘₯ = (
)π›₯𝑑2
π‘š
π‘š
0 + 350
𝑠 )(0.0050𝑠)
π›₯π‘₯ = ( 𝑠
2
π›₯π‘₯ = 0.88 π‘š, πΈπ‘Žπ‘ π‘‘
4. Generalization
“What equation you may
"𝑣𝑓 = 𝑣𝑖 + π‘Žπ›₯𝑑 (Equation 1)”
use in problems that do not
directly
involve
displacement.”
“What equation will allow
you to determine the
displacement of an object
moving
with
uniform
acceleration given a value
for acceleration rather than
a final velocity?”
π›₯π‘₯=𝑣 𝑑+1 π‘Žπ›₯𝑑2
𝑖
2
(Equation 2)
“What equation you may
use in problems that do not
directly involve time?”
“𝑣𝑓2 = 𝑣𝑖2 + 2π‘Žπ›₯π‘₯(Equation 3)
“What equation you will use
to
determine
the
displacement of an object
π›₯π‘₯ = (
𝑣𝑖+𝑣𝑓
2
)π›₯𝑑 (Equation 4)
that is undergoing uniform
acceleration.”
“Very good!”
IV. Evaluation
A car has uniformly accelerated from rest to a speed of 25m/s after travelling
75m. What is its acceleration?
V. Assignment
1. A plane has a takeoff speed of 88.3 m/s from rest and requires 1365 m to
reach that speed. Determine the acceleration of the plane and the time required to
reach this speed.
Download