Transcript Unit 4: Force

S8P3. Students will investigate relationship between
force, mass, and the motion of objects.
Unit 4: Force
S8P3. Students will investigate
relationship between force, mass, and
the motion of objects.
EQ: What is velocity and acceleration?
EQ Answer:
P. 89
LG1: I will be able to compare, contrast, and
calculate speed, velocity, and acceleration. I will
understand force and apply Newton’s Laws in
real-life situations.
LG2: I will be able to compare, contrast, and
calculate speed, velocity, and acceleration
through word problems. I will use Newton’s Laws
in real-life situations through problem-solving.
LG3: I will be able to compare, contrast, and
calculate speed, velocity, and acceleration
through word problems and graphs. I will use
Newton’s Laws in real-life situation through
problem-solving by using graphs.
Motion – occurs when an object changes
position relative to a reference point.
A Reference Point is something you use to
determine the position of an object, but
the reference point has to be something
that doesn't move.
Draw this
Distance Vs. Displacement
Distance – how far an object has traveled
Displacement – distance and direction of
an objects change in position from
starting point.
W
Speed – the distance an object travels in a
certain amount of time.
Average Speed = total distance
total time
s=d
t
There are 3 types of speed:
Instantaneous Speed – speed at any given
point in time
Ex. Driving a car and looking down at
the speedometer.
Average Speed – total distance traveled
divided by total time
Ex. Taking a road trip
Constant Speed – Speed that does not
change
Ex. Putting car in cruise control
Velocity – includes speed of an object and
the direction of its motion.
(Speed + direction)
Check This out!
https://www.youtube.com/watch?v=mDcaeO0WxBI
Speed Vs. Velocity
Speed
Velocity
Acceleration occurs when an object
changes speed, its direction, or both.
Acceleration – rate of change of velocity.
Acceleration = change in velocity
time
a = final velocity – initial (starting velocity)
time
It is possible to have a positive and
negative acceleration!
Positive Acceleration – A plane takes off
Negative Acceleration – A bike comes to a
stop
Calculating Speed, Velocity, and
Acceleration
Follow these steps when working out a
formula/word problem:
1. Read the problem
2. Circle what they are asking for
3. Find the formula you use
4. Write the formula
5. Plug in the numbers
P. 93
Formulas:
Speed
S=d
t
Velocity
v= d
t
Acceleration
a = v(f)-V(i)
t
1.
Distance: 25 m Time: 5 seconds
2.
Time: 30 seconds Speed: 7 m/s
3.
Speed: 5 miles/hr Distance: 45 miles
Sam is on his way to his friends house. He
lives 20 miles away and he needs to get
there in 5 minutes. What speed should
he go to make that happen?

Juan stands at the starting line of a race
track. He leaps forward as the starting
gun blasts, and runs straight toward the
finish line. When he crosses the finish
line 2 seconds later, he is clocked at 9
meters/second. How many meters did
he run?
Kristy wants to ride her bike around the
block going 2 miles/hour. From her
driveway and back is 8 miles. How long
did it take her to ride her bike?
Jim decides to take a road trip. His house
to Atlanta is 420 miles. He wants to get
there in 7 hours. How fast should he go
to make it there in time?

Initial velocity: 20m/s
final velocity: 60m/s
time: 2 s
Good Morning!

Pick up the worksheet with a circle on it
and cut it out.
Speed
Distance
Time
When solving a problem
Read the problem
Circle what it is asking for
Find the formula
Write the formula
Plug in the numbers
A car travels along a road at a steady
speed of 60 mph. How far will it travel in
6 hours?
A train covers a distance of 480 miles in 8
hours. If it travels at a constant speed,
how fast is it traveling?
John walks at a steady speed of 3 mph.
How long will it take him to travel 24
miles?
A car travels at a constant speed of 65
mph. How far will it have traveled in 4
hours?
Melanie completes a long distance run at
an average speed of 6 mph. If it takes
her 3 hours, how far did she run?
Sarah cycles 30 miles to her
grandmother’s house at a steady speed
of 10 mph. If she leaves home at 2:00
P.M., what time will she arrive?
Quiz
Acceleration
EQ: What does velocity and acceleration
have in common?
EQ Answer:
P. 99
Acceleration can be positive or negative.
Acceleration – rate of change of velocity
Formula:
A= final v – initial v
t
These graphs show the change in
velocity/speed. Remember that velocity
and speed have the same formula
except velocity includes direction.
*** The line is speed/velocity.
Foldable
Practice A Graph
Glue here
Positive
Practice B Graph
Glue here
Negative
Positive Flap:
Distance increases as time increases.
The car traveled on I-16 heading West
(velocity). When the car pulled on the on
ramp, the car was traveling 45mph. In 1
hour the car was traveling at 75mph.
What was the acceleration?
Negative Flap
Distance decreases as time increases.
The car sees a stop sign up ahead when
the car is traveling North (velocity). The
car is traveling at 25 m/s. In 5 seconds,
the car is stopped. What is the
acceleration?
Force
EQ: What is force?
EQ Answer:
P. 101
Force – A push or pull applied to an object
Net Force – when two or more forces act
on an object at the same time.
Only when forces are unbalanced is when
an object moves!!!!
A balanced force is where the both forces
applied are equal!
An unbalanced force is where forces are
unequal.
Today we will be creating two comic strips.
Once on balanced forces and the other
on unbalanced forces.
Lets review:
https://www.youtube.com/watch?v=K3S6WKJIohw
https://www.youtube.com/watch?v=CsgGZ4EjWoM
Your descriptions should answer these questions:
What is your comic strip about?
How did you come up with this example?
Why is it balanced/unbalanced force?
Please include these key words:
Force
Net Force
P.103
Friction
EQ: What are the four types of friction?
EQ Answer:
P. 104
Friction – the force that opposes the
sliding motion of two touching surfaces.
There are 4 types of friction: static, sliding,
rolling, and fluid.
https://www.youtube.com/watch?v=MAqrWvkBoHk
Type of Friction Description
Example
Static
Friction in which two surfaces are
not moving past each other.
Sliding
Friction where two surfaces slide
past one another.
Sledding down a hill
Rolling
Friction between a rolling object
and surface it rolls on.
Skateboard moving on
ground
Fluid
Friction when object moves
through fluid, meaning either a
liquid or gas.
Skydiving
Air Resistance – friction-like force that
opposes motion of objects that move
through air.
With air resistance, depends on speed,
size and shape of object.
Cut out the pictures….

Look at the pictures and try to figure out
which picture belongs to what type of
friction.

DO NOT GLUE!!!!!!!!!!!!!!!
Friction Foldable
Take the paper and make a sailboat
and cut off the extra
Then fold corners in.
Static

Two surfaces not moving past each
other.
Sliding

Two surfaces slide past one another.
Rolling

Occurs when an object rolls over
another

(something with wheels or an object that
is round)
Fluid

Occurs when object moves through a
fluid, either a liquid or gas.

(anything in water and sometimes
through gas)
Friction Labs
Walk through every lab with your partner
and answer the questions on your lab
sheet!
 When you are done, I want you to go
back to your desk and give me
examples of each type of friction from
your own life.

Come on in…
Please fold paper and glue on p. 107
Read and highlight key sentences in
article.
Gravity
Gravity – any two masses that exert a
force on each other
Gravity depends on mass and distance
between objects.
P. 108
Weight – gravitational force exerted on an
object.
The greater the objects mass, the stronger
the gravitational force on it.
(The bigger the object, the more
gravitational force on it)
1st Law of Motion
EQ: What is the 1st Law of Motion and
what does it mean?
EQ Answer:
P. 109
Sir Isaac Newton is a very well known
scientist. He created the 3 Laws of
Motion. This is why we measure force in
Newtons.
Inertia – tendency of an object to resist
any change in its motion.
Newton’s First Law of Motion
(AKA Law of Inertia)
An object in motion stays in motion, or an
object at rest stays at rest until an
unbalanced net force acts upon it.
WAIT… WHAT…????
That means that an object will keep
moving until a force changes that or an
object will stay at rest until a force
changes it.
Experiment: We are going to put an index
card on a cup with a penny on it.
Hypothesis: (What do you think will
happen to the penny on top?)
Conclusion: (In your words, what did your
penny do? Was your hypothesis right or
wrong?)
Draw the experiment:
Good Afternoon!

Please come in and reread the article on
page 107

You will be tested on this article.
Review:
https://www.youtube.com/watch?v=pxWHWOYVov4
POP QUIZ!

I will give you five minutes to study!!!
Please use it.
WORD BANK
+10 Points
BONUS:
ONLY FOR WORDS 1-4
What is the first
law of motion?
Rolling
Static
Sliding
Fluid
2nd Law of Motion
EQ: What is the 2nd Law of Motion and
what does it mean?
EQ Answer:
Newton’s Second Law of Motion
A net force acting on an object causes the
object to accelerate in the direction of
the force.
Acceleration is determined by amount of
force and the mass of an object.
Formula:
Force = mass X acceleration
F=m X a
WHAT DOES THIS MEAN????
It means that the heavier/more mass the
object has, the more force you have to
use to make it accelerate.
https://www.youtube.com/watch?v=nO7XeYPi2FU
Experiment: We have two water bottles the
same size. One will be completely full
while the other will be half full. We will
pull both objects with the same force.
Hypothesis: (Which one do you think will
move faster?)
Conclusion: (Why did one move faster
than the other. Use the 2nd Law of
Motion)
Draw the experiment under your
conclusion.
https://www.youtube.com/watch?v=iwP4heWDhvw
Good Afternoon!
Please come in and reread the article on
page 107.
You will be tested over this.
3rd Law of Motion
EQ: What is the 3rd Law of Motion and
what does it mean?
EQ Answer:
Momentum – property of moving object
resulting from its mass and velocity.
Momentum (p) = mass X velocity
Newton’s Third Law of Motion
For every action (or force), there is an
equal and opposite reaction (of force).
https://www.youtube.com/watch?v=MUgFT1hRTE4
Experiment: We are going to put a straw in
a balloon and blow the balloon up with
air. We will tape the balloon to a car and
let the air out.
Hypothesis: (What do you think will
happen to the car when we let the air
out?)
Conclusion: (What did happen to the car
and why? Include the 3rd Law of Motion
in your answer.)
Draw the experiment.
https://www.youtube.com/watch?v=_sr3hBxu614
https://www.youtube.com/watch?v=pxWHWOYVov4
How does this video show the 1st Law of
Motion and the 3rd Law of Motion???
Answer in complete sentences.
Newton’s Laws Foldable
Laws of Motion Project
Pick which Law of Motion you would like to
work on (1st, 2nd, 3rd)
You have to include information about:
Isaac Newton
The actual Law of Motion
What does it mean in your own words
4-5 Picture examples
Good Afternoon

Voice Level
=0
Come on in and read the article on your
desk.
Balanced and Unbalanced Forces
EQ: What is a balanced and unbalanced
force?
EQ Answer: (Skip 3 lines)
Net Force – two or more forces acting on
an object at the same time.
Balanced Force – is an equal force but in
opposite direction.
NO CHANGE IN MOTION!!!!!
Net force = 0
Unbalanced Force – a force is greater than
the others put on an object.
Net force = Positive #
Draw this in
notebook:
Balanced
Unbalanced
Cut out the pictures an place them in the
right category.
BEFORE YOU GLUE, RAISE
YOUR HAND TO LET ME
CHECK!!!!!!
Balanced
Unbalanced
Give an example of a balanced force in
your life:
Draw a picture:
Give an example of an unbalanced force in
your life:
Draw a picture: