Concept Presentation
Projectile Motion
Presenter: Nate Mohanlall
22nd July 2010
Mentor: Sean Henderson
http://www.colorado.edu/physics/phys1110/phys1110_fa07/mainPage3.html
Overview
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Curriculum Placement/Expectations
Lesson Sequence/Teaching Ideas
Projectile Motion Misconceptions / Concepts
Strategies for solving problems
Applications and Societal Implications
Assessment and Evaluation
Curriculum Placement: BIG IDEAS
Grade 2 : Structures
 investigate and describe different kinds of movement (e.g., by observing how toys and
other everyday objects move)
 identify ways in which the position of an object can be changed (e.g., by pushing, by
pulling, by dropping)
Grade 11 Physics: Kinematics
 Motion involves a change in the position of an object over time.
 Motion can be described using mathematical relationships.
 Many technologies that apply concepts related to kinematics have societal and
environmental implications.
Grade 12 Physics: Dynamics
 Forces affect motion in predictable and quantifiable ways.
 Forces acting on an object will determine the motion of that object.
 Many technologies that utilize the principles of dynamics have societal and
environmental implications.
A1. Scientific Investigation Skills
 A1.5 conduct inquiries, controlling relevant variables,
adapting or extending procedures as required, and
using appropriate materials and equipment safely,
accurately, and effectively, to collect observations and
data
 A1.10 draw conclusions based on inquiry results and
research findings, and justify their conclusions with
reference to scientific knowledge
 A1.12 use appropriate numeric (e.g., SI and imperial
units), symbolic, and graphic modes
 of representation (e.g., vector diagrams, free-body
diagrams, vector components, and Algebraic
equations)
B2. Developing Skills of Investigation and Communication
 B2.1 use appropriate terminology related to dynamics,
including, but not limited to: inertial and non-inertial frames
of reference, components, centripetal, period, frequency,
static friction, and kinetic friction [C]
 B2.2 solve problems related to motion, including projectile
and relative motion, by adding and subtracting twodimensional vector quantities, using vector diagrams, vector
components, and algebraic methods [PR, AI, C]
C1. Relating Science to Technology, Society, and the Environment
 B1.1 analyse a technological device that applies the
principles of linear or circular motion (e.g., a
slingshot, a rocket launcher, a race car, a
trebuchet) [AI, C]
 B1.2 assess the impact on society and the
environment of technological devices that use
linear or circular motion (e.g., projectile weapons,
centrifuges, elevators) [AI, C]
Lesson Sequence
Day 1
Description of Activity
Day 1:
-Diagnostic lab
:Projectile motion
-Vocabulary :
Complete
graphic organizer
Using textbook
Teaching/Learning
Strategies
Expectations
Addressed
Learning
-Group work
-Independent
work:
Complete Graphic
Organizer
-Demo Projectile
Motion (to
reinforce concept
quiz)
A1.5
A1.10
A1.12
B1.1
B2.1
Kinesthetic/
Tactile
Visual
Linguistic
Assessment
Styles
Diagnostic
-observe students
as they complete
graphic organizer
and perform lab
-Concept quiz
Class Activity
What type of motion is the marble experiencing vertically?
What type of motion is the marble experiencing horizontally?
http://media.ehs.uen.org/html/PhysicsQ2/Horizontal_Projectiles_03/ramp.jpg
Graphic Organizer
Key Terms
Horizontal Velocity
Vertical Velocity
Range/Max. Horizontal Range
Uniform Motion
Uniform Accelerated Motion
Time of Flight
Maximum Height
Etc.
Definition/Explanation
What do the following situations have
in common?
 A truck is equipped with a flare
launcher which is capable of
launching a sphere vertically
(relative to the truck).
 A relief package drops from a lowflying airplane.
1.
Suppose a truck is equipped with a flare
launcher which is capable of launching a sphere
vertically (relative to the truck). If the truck is in
motion and launches the flare and maintains a
constant horizontal velocity after the launch,
then where will the flare land (neglect air
resistance)?
a. in front of the truck
b. behind the truck
c. in the truck
http://www.physicsclassroom.com/mmedia/vectors/tb.cfm
2. Suppose a rescue airplane drops a relief
package while it is moving with a constant
horizontal speed at an elevated height.
Assuming that air resistance is negligible,
where will the relief package land relative to
the plane?
a. below the plane and behind it.
b. directly below the plane
c. below the plane and ahead of it
http://www.physicsclassroom.com/mmedia/vectors/pap.cfm
Lesson sequence
Day 2 and 3
Description of Activity
Day 2 and 3:
1. Discuss how objects
release from the same
height and projected
horizontally and with
different masses hit
the ground the same
time.
2. Parabolic motion and
angle of projection
3.
Comparing Horizontal
Range :Using formula
to verify maximum
possible range using
different angles and a
fixed initial velocity
Teaching/
Learning
Strategies
-Demo- using
two object
With
Different
masses
-Animation
Investigation
Group work
Textbook
Expectations
Addressed
Learning Styles
Assessment
B2.1
B2.2
Visual
Auditory
Kinesthetic/Tactile
Interpersonal
Formative
Checking for
understanding
Questioning of
students based
on their
mathematical
knowledge
Solve for
maximum range
using formula
-concept quiz
Lesson sequence
Day 4
Description of Activity
Teaching/
Learning
Strategies
Expectations
Addressed
Learning
Styles
Assessment
Day 4:
1.Problem Solving
-Analyzing the motion of
objects projected horizontally
-Analyzing more complex
projectile motion
-Class work
-Direct
B2.1
B2.2
B2.3
Kinesthetic
Visual
Auditory
Formative
-Circulate while students
individually solve problems
to observe students’
readiness
-Concept Circle
-Parallel Questioning
-assignment
Summative
-Quiz, Test
Instruction,
student involve
-Problem Solving
Strategies
-Independent
work
-Compiling
Physics Toolbox
Concept Circle
Concept:____________
Modify the strategy by:
 leaving one section empty,
to be filled by students;
 including one non-example
and asking students to find
which item does not
belong and to justify their
answer.
Physics Toolbox
Kinematics Equations for Projectile Motion
Description
Formula
Horizontal (x) Motion
Vertical (y) Motion
Quadratic Formula
Horizontal Range
etc
etc
Differentiating Physics Instruction
Parallel Questions
Task 1
Task 2
A child travels down a water slide, leaving it with a velocity of
4.2 m/s horizontally. The child then experiences
projectile motion, landing in a swimming pool
3.2 m below the slide.
(a) For how long is the child airborne?
(b) Determine the child’s velocity upon entering the water.
A helicopter, travelling horizontally, is 82 m above the
ground. The pilot prepares to release a relief package
intended to land on the ground 96 m horizontally ahead. Air
resistance is negligible. The pilot does not throw the package,
but lets it drop. What is the initial velocity of the package
relative to the ground?
Misconception # 1
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Students develop personal “theories of motion” by generalising the ideas they acquire from observation of objects in
everyday situations (Keeports, 2000)
 Heavier objects fall faster.
Addressing Misconception # 1
 Animation are useful tools
for visual learners.
 Here we see that heavier
objects hit the ground at
the same time as lighter
ones.
http://library.thinkquest.org/2779/
Misconception # 2
 If one object is dropped from a
specific point and another is
projected forward from the same
point, then the projected object will
take longer to reach the ground.
Let’s Consider…
Ball A falls freely from a specific height and at
the same time ball B is thrown horizontally
from the same height.
(a) How do we compare the acceleration of the
two balls.
(b) Which ball will hit the ground first? Why?
Nelson: Physics 12 p.41
Addressing Misconception # 2
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This animation shows
that both objects
reach the ground at
the same time.
this illustrates the
concept in a different
way for Visual
learners
Nelson: Physics 12 p.41
http://library.thinkquest.org/2779/
Misconception # 3
Parabolic Motion
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Showing the parabolic nature of projectiles
leads the student to believe they are quite
different from linear falling or horizontal
motion
Addressing Misconception # 3
 An easy way to deal with this is to plot the motion
of a freely falling object and a horizontally moving
object on the same graph.
 When the intersection points at the same time,
are connected, the result is a parabola.
Addressing Misconception # 3
 The green ball illustrates
uniform motion
 The red ball illustrates free
fall and uniform accelerated
motion
 The combination of these two
motions at equal time
intervals yields the parabolic
path shown by the blue ball!
 Horizontal and vertical
motion are independent of
each other
http://www.physicsclassroom.com/mmedia/vectors/bds.gif
Misconception # 4
Parabolic Motion
 At the top (peak) of its trajectory, the
velocity of a projectile is always momentarily
zero.
 The acceleration of the object is also zero, at
the peak.
Let’s Consider
A basketball ball is thrown at an angle from one
person to another.
1. What is the velocity of the object at the peak
of the flight?
2. What is the acceleration of the object at the
peak of the flight?
Addressing Misconceptions # 4
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Have students look at the horizontal and vertical velocity vectors
throughout parabolic flight.
Demonstrate that the velocity is not zero as there must be some
horizontal motion still (it doesn’t stop in midair).
# 4 Cont’d
 If you throw an object in the air, it stops briefly (vertical
velocity is zero) but acceleration is not zero (gravity doesn’t
stop).
What is its role?
 To change the direction of the velocity vector.
http://www.physicsclassroom.com/Class/vectors/U3L2c.cfm
Misconception # 5
Students believe that the greater the angle
of projection, the greater the horizontal
distance travelled by a projectile.
Class Activity Nelson Physics 12:
Comparing Horizontal Range p.49
Use formula to verify
Can you spot the
Mistake in this
animation?
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
Strategies for solving problems
 Frame the Problem
 Identify the Goal
 Variables and Constants
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Involved in the problem
Known
Implied
Unknown
 Strategy
 Calculations
 Validate
McGraw-Hill Ryerson Physics 11
Applications and Societal
Implications
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Sports
Projectile Weapons
Forensic
Forest Fire
Circus/fireworks
Drop food in disaster areas
Assessment and Evaluation
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Assignment
Quiz
Test
Lab
Monkey and Banana
Problem
Monkey and Banana
Throw at the Monkey in a Gravity Free Environment
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
Throw above the Monkey with Gravity On
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
Throw at the Monkey at a Fast Speed with Gravity On
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
Throw at the Monkey at a Slow Speed with Gravity On
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
References
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http://www.lon-capa.org/~mmp/kap3/cd060.htm
http://www.walter-fendt.de/ph14e/projectile.htm
http://www.falstad.com/mathphysics.html
http://www.physicsclassroom.com/mmedia/vectors/mzi.cfm
Keeports, D. (2000). Addressing physical intuition-a first day event. The
Physics Teacher,38, 318-319.