Transcript newton`s 1st law pp

Isaac Newton was an
English Scientist
In 1667, he developed
3 laws of motion that
described movement of
objects in terms of forces
These laws of motion still hold true today
What is a Force?
FORCE = Any push or pull which causes
something to move OR
change its speed or direction
What is a Force?
Forces can be BALANCED or UNBALANCED


Balanced forces are equal in size and opposite
in direction
Unbalanced forces are not equal in size
and/or opposite in direction.
OR

If the forces on an object are UNBALANCED,
we say a NET force results.
What is Friction?
Friction = A force that opposes or slows down
motion
 Caused by the physical contact between
moving surfaces
 The amount of friction depends upon the
kinds of surfaces and the force pressing
the surfaces together
 Friction changes motion into heat
First Law: An object at rest stays at rest or an

object in motion, stays in motion (in the
same direction/at the same speed) unless
acted upon by an unbalanced force
Also called the law of inertia
Inertia



The tendency of an object to resist any
change in its motion
The greater the mass the greater the inertia
The greater the speed the greater the inertia
Examples of Newton’s 1st Law
a) car suddenly stops and you strain
against the seat belt
b) when riding a horse, the horse
suddenly stops and you fly over its
head
c) the magician pulls the tablecloth out
from under a table full of dishes
d) the difficulty of pushing a dead car
VIDEO
Newton’s First Law
Person pushes
wheelbarrow at constant
velocity
.
No net force acts
on rake. Rake
continues moving
forward.
Wheelbarrow strikes rock.
Rock exerts a net force on
wheelbarrow causing it to
decelerate.
feet
Discussion Questions
1. What are the differences in how balanced
and unbalanced forces affect motion?
2. What is inertia? How is it involved in
Newton’s 1st Law of Motion?
3. Two children who are fighting over a toy pull
on it from opposite sides. The result is a
standoff. Explain this in terms of the net
force.
Circles are linked to open slides to use Interwrite pad for student responses. Teacher may write student
responses or let students write responses and explain.
End
1. Balanced/Unbalanced
2. Interia
3. Net Force
Tricky Tricks
Lab Procedure
1. Fill a beaker with water.
2. Cover the beaker with an
index card
3. Place a penny in the
center of the card
4. Hold the base of the cup
with it resting on the
table
5. Use your index finger to
flick the card.
Discussion QUESTIONS to be
written in you Science
Journal. Write title and
questions with answers.
1. How does this activity relate
to the “pull the tablecloth”
trick used by magicians?
2. Explain your observations
using the vocabulary word
inertia?
Football in
Motion
Football at
Rest
Skateboard
in motion
Skateboard
at rest
Mass/Force
Small
Mass/Force
Large
Equal/
Opposite
Small
Equal/
Opposite
Large
The End
Click on the hyperlinks to view the videos.
Multimedia Project : Newton's Laws of Motion Video Rubric
Teacher Name: Mrs. Holmes
Student Name:
________________________________________
CATEGORY
Content
Presentation
4
3
Covers topic in-depth
Includes essential
with details and
knowledge about the
examples for each Law. topic. Subject knowledge
Subject knowledge is
appears to be good.
excellent.
Well-rehearsed with
Rehearsed with fairly
smooth delivery that
smooth delivery that
holds audience attention. holds audience attention
most of the time.
2
1
Includes essential
information about the
topic but there are 1-2
factual errors.
Content is minimal OR
there are several factual
errors.
Delivery not smooth, but Delivery not smooth and
able to maintain interest audience attention often
of the audience most of lost.
the time.
Organization
Content is well organized Uses transitions to
Content is logically
using transitions to group organize, but the overall organized for the most
related material.
organization of topics
part.
appears flawed.
Requirements
All requirements are met All requirements are met. One requirement was not More than one
and exceeded. Each Law
completely met.
requirement was not
has question and
completely met.
description of the Law.
Workload
The workload is divided The workload is divided The workload was
and shared equally by all and shared fairly by all divided, but one person
team members.
team members, though in the group is viewed as
workloads may vary from not doing his/her fair
person to person.
share of the work.
Technology
Student selected
appropriate technology
and checked it prior to
presentation. Everything
worked well.
Student selected
appropriate technology
but, presentation did not
work completely.
There was no clear or
logical organizational
structure, just lots of
facts.
The workload was not
divided OR several
people in the group are
viewed as not doing their
fair share of the work.
Student selected
Student must redo
appropriate technology project because it did not
but, presentation did not work at all.
work .
Date Created: Jun 05, 2009 11:36 am (CDT)
This is the Rubric that will be used for students to create your own Video
Project.
Sources:
www.brainpop.com
www.rubistar.com
http://www.youtube.com/watch?v=F_yyCS49D6k
http://www.youtube.com/watch?v=4LfJ081mLEk&NR=1
http://www.youtube.com/watch?v=T9KPwNeCdSg&NR=1
http://www.youtube.com/watch?v=V6sXTsB_oS4&NR=1