Transcript Unit 5: Physics in Action

UNIT 5:
PHYSICS IN
ACTION
ESSENTIAL
QUESTIONS
-
What is inertia, acceleration, and gravity?
-
What are Newton’s 3 Laws of Motion and how can they be
applied to everyday principles?
-
How does a person’s center of mass effect their balance
and performance?
-
What is vertical accelerated motion and how can this be
applied to athletic jumping?
-
How does the surface effect the force due to friction, and
how does this affect an athlete’s performance?
-
What is momentum and how is it conserved?
CHAPTER CHALLENGE
– DUE JANUARY 30
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You will need to find a 2-3 minute sports clip (can be
recorded from TV or downloaded from the internet) of a
sport that you enjoy watching/participating in
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You may work individually or with a group (max. 3 people)
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You will explain the physics principles behind the sport
clip by either:
-
Submitting a written script
Performing a live narrative
Dubbing onto the video soundtrack
Recording on file
DAY 1: A RUNNING
START
Learning Objectives:
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Understand and apply Galileo’s Principle of Inertia
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Understand and apply Newton’s First Law of Motion
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Recognize inertial mass as a physical property of matter
STARTER
Watch the following videos and answer the questions:
-
What determines the amount of horizontal distance a
basketball player travels while “hanging” to do a slam
dunk during a fast break?
-
How do figure skaters keep moving across the ice at a
high speed for long periods of time while seldom pumping
their skates?
Time: 15 minutes
ACTIVITY 1
Newton’s First Law of Motion
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Place some water in a plastic beaker.
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Place a piece of paper under the beaker.
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Try to remove the paper without spilling any water
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Try this again using a different amount of water. Any
change?
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Create a definition for Newton’s first law of motion based
on what you observed
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Time: 20 minutes
ACTIVITY 2
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Make a target on a piece of paper
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You are going to try to hit the target with a tennis ball as
you run past it
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Make any changes to your definition for Newton’s first law
of motion based on what you observed
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Time: 20 minutes
ACTIVITY 3
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Complete steps 1-4 on pages 5 & 6
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Record your data in a table you create
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Time: 25 minutes
CLOSING &
HOMEWORK
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What does Newton’s First Law of Motion state?
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Why is a ball’s return height not a mirror image when you
roll it down a ramp?
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For you to read/Physics talk, page 8-12
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Physics to go, pg. 13 # 1, 4, 5, 6, 8, 9
DAY 2: ADDING
VECTORS
Learning Objectives:
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Recognize that a force is a push or pull
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Identify the forces acting on an object
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Determine when the forces on an object are either balanced or
unbalanced
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Calibrate a force meter in arbitrary units
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Use a force meter to apply measured amounts of force to objects
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Compare amounts of acceleration semi-quantitatively
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Understand and apply Newton’s Second Law of Motion
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Understand and apply the definition of the newton as a unit of
force
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Understand weight as a spatial application of Newton’s Second
Law
STARTER
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What is a force?
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What is Newton’s Second Law of Motion?
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If you apply the same amount of force to the shot put and
the tennis ball,
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- Will they move the same distance?
- Will one ball move farther than the other?
- Why?
Time: 15 minutes
ACTIVITY 1
Choose 4 various masses and record their weight in
newtons. Check that the mass is correct by taking the mass
on the electronic scale.
Mass (kg)
Force (N)
Acceleration (m/s2)
How will acceleration be calculated?
What do you notice about the acceleration of each mass?
What does this number represent?
Time: 25 minutes
ACTIVITY 2
F = ma
a = F/m
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Take a coffee mug and find its mass
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Slide the coffee mug across the table at a slow, constant
speed. Record the force used to pull the mug.
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Repeat, this time sliding the mug at a faster rate. Record
the force used to pull the mug.
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Calculate the acceleration in both cases. What conclusion
can you make?
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Time: 15 minutes
ACTIVITY 3
We will go to the computer lab to go through 2 activities:
http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_
forces/
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Go to “Forces” and do the “revise”, “activity”, and “test”
http://learner3.learner.org/interactives/parkphysics/bumperca
rs/
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Work through the bumper car problems
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Time: 30 minutes
CLOSING &
HOMEWORK
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Read physics talk/for you to read, Pg. 18-22
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Physics to go, Pg 23. #1, 2, 5, 9
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Choose any 3 calculation questions from #3, 4, 11-18
DAY 3: CENTER OF
MASS
Learning Objectives:
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Locate the centre of mass of oddly shaped 2-D objects
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Infer the location of the cenre of mass of symmetrical 3-D
objects
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Measure the approximate location of the centre of mass of
body
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Understand that the entire mass of an object may be
thought of as being located at the object’s centre of mass
STARTER
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Watch the video of the world high jump record being set
(2.45m) by Javier Sotomayor. Sotomayor is 1.95m tall.
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Think of the following questions after you watch:
-
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What is center of mass? What does this mean?
Where is your body’s center of mass?
The high jump technique to get over the bar is called the
Fosbury Flop. Where is the person’s center of mass when
they are trying to get over the high jump bar?
Time: 15 minutes
ACTIVITY 1
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Cut out the shapes from the templates onto construction
paper
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Draw the shapes in your notebook as well
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For shapes A, B, and C, try to locate the object’s center of
mass
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- Where will the object balance on your finger?
Mark the balance points on your sketch in your notebook
and on your object
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Time: 30 minutes
ACTIVITY 2
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You will now test to see if your balance point was accurate
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Follow steps 3-7 on pp. 28-29
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Record the answers to the questions in your notebook as
you go along
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Time: 40 minutes
ACTIVITY 3
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Watch the following videos to determine the athlete’s
center of mass
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How do you make a football player fall?
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What do you notice about the gymnast’s center of mass?
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Time: 10 minutes
CLOSING &
HOMEWORK
Physics to Go, pg. 30, #1, 2, 3, 5
DAY 4: DEFY GRAVITY
Learning Objectives:
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Measure changes in height of the body’s center of mass
during a vertical jump
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Calculate changes in the gravitational potential energy of
the body’s center of mass during a vertical jump
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Understand and apply the definition of work
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Recognize that work is equivalent to energy
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Understand and apply the joule as the unit of work and
energy
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Apply conservation of work and energy to the analysis of
a vertical jump
STARTER
“No athlete can escape the pull of gravity.”
From previous videos:
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Was Michael Jordan able to defy gravity when he went up for
his slam dunk?
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Was Katarina Witt able to defy gravity while doing a double
axel?
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Did Javier Sotomayer defy gravity when breaking the world
record for high jump?
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Did Dominique Dawes defy gravity when she did a doubleback in the air?
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Explain your answers
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Time: 15 minutes
ACTIVITY 1
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Watch the video of the skater doing a triple axel
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You will count the number of frames the skater is in the air
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- Each frame appears to be “jerky”
Each frame is 1/30 seconds
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You will calculate the skater’s “hang time”
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- Time in air = Number of frames x 1/30
Watch the video of the basketball player doing a slam
dunk
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Calculate the basketball player’s “hang time”
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Did either athlete “hang” in the air? Explain.
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Time: 15 minutes
ACTIVITY 2
You will work with your group to analyze a vertical jump
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Complete steps 3-8 on pp. 32-34
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Record your data and answers as you go along
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1 answer sheet/group will be handed in at the end of the
lesson
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Time: 35 minutes
CLOSING &
HOMEWORK
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Read “for you to read”, pp. 35-39
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Read “physics talk”, pp. 40-42
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Physics to go, pp. 43-44, Choose any 6 calculations
Formulas:
Work (J)= Force (N) x distance (m)
Work (J) = Kinetic energy (J) = Potential energy (J)
Potential energy (J) = Mass (kg) x acceleration due to gravity
(9.8m/s2) x height (m)
Kinetic energy (J) = ½ x Mass (kg) x velocity2 (m/s)
DAY 5: RUN AND JUMP
Learning Objectives:
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Understand the definition of acceleration
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Understand meters per second per second as the unit of
acceleration
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Use an accelerometer to detect acceleration
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Use an accelerometer to make comparisons of
acceleration
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Distinguish between acceleration and decceleration
STARTER
Pretend you have met somebody who has never jumped
before.
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What instructions would you provide to get the person to
jump up?
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Where do they need to apply force?
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What actions do they need to do?
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Give instructions to someone in your group to see if they
are accurate
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Time: 15 minutes
ACTIVITY 1
Pg. 45, step 1
ACTIVITY 2
Pg. 46, step 2, 3
ACTIVITY 4
Pg. 47, step 4-6
CLOSING &
HOMEWORK
Physics to Go
-Pg. 48 #1, 3, 6
Stretching Exercise
-If you have access to an elevator, complete the exercise
-If you don’t, watch a clip on Youtube showing what happens
to the needle on a bathroom scale when you are in an
elevator
DAY 6: THE MU OF
THE SHOE
Learning Objectives:
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Understand and apply the definition of the coefficient of
sliding friction, μ
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Measure the coefficient of sliding friction between the
soles of athletic shoes and a variety of floor surfaces
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Calculate the effects of frictional forces on the motion of
objects
STARTER
A shoe store may sell as many as 100 different kinds of
sports shoes.
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Look at the pictures and explain the difference between
the shoes
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Why do different sports require different shoes?
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What shoes would the sports be used for?
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Time: 15 minutes
ACTIVITY 1
Follow steps 1-4 on pg. 50-52
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Use any shoe you want, you may want to use 2 different
shoes to compare how the soles of the shoe affect how it
slides across 2 different surfaces
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Surface choices:
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- Smooth: table, tiles at back of room, lab bench surface
- Rough: carpet, grass, cement walkway
For the “filler”, you can use the masses on the back table
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Time: 45 minutes
ACTIVITY 2
Calculations
Your running shoe has a weight of 3.5N. The shoe slides across a
surface when a horizontal force of 12N is applied to it. What is the
coefficient of sliding friction?
What do you know?
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Force to slide shoe = 12N
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Weight of shoe = 3.5N
Solve:
μ = force required to slide object on surface at a constant speed
perpendicular force exerted by the surface of the object
= 3.5N
12
= 0.29
CLOSING &
HOMEWORK
You may use this time to work on your chapter challenge
Homework:
-
Read Physics Talk, pg. 53
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Physics to Go, pg. 54-55 #1, 2, 3, 4, 5
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Assignment, pg. 55 #8
DAY 7: CONCENTRATING
ON COLLISIONS (60
MINS)
Learning Objectives:
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Understand and apply the definition of momentum
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Conduct quantitative analysis of the momentum of pairs of
objects involved in 1-D collisions
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Infer the relative masses of two objects by observing
collisions between the objects
STARTER
In contact sports, very large forces happen during short time
intervals.
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Name 3 sports where collisions happen, and what the
collisions are in the sports
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If 2 athletes have a head-on collision, what factors
determine which player will make it through the collision?
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Time: 15 minutes
ACTIVITY 1
Complete steps 1-7 on pp. 56-58
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Balls to use are on the back lab bench
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Wood pieces to assemble ramps are on back lab bench
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Record observations and answer questions as you go
along
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Hand in 1/group when completed
CLOSING &
HOMEWORK
Physics to Go, pg. 59 #1, 2, 3, 6
DAY 8: SUMMATIVE
ASSESSMENT
Presentation of Commentary on Sporting Event