IB PHYSICS – Year 1
(SECONDARY)
ESSENTIAL UNIT 5 (EU5)
UNIFORM CIRCULAR MOTION AND PROJECTILE MOTION
(2011)
Unit Statement:
When an object moves in a circular trajectory, no matter whether the motion is happening at a
constant speed or not, the net force acting on the object is not zero Newtons. Circular motion is always
accelerated.
The description of projectile motion can be simple or very complicated when air resistance and non
uniform force fields are involved. Only the simplest cases are treated mathematically (uniform force
fields and no friction with air). The effects of air resistance are described only qualitatively.
SL students should not be required to complete the Projectile Motion TSWs. It is only required for the
HL students.
Essential Outcomes: (Must be Assessed)
UNIFORM CIRCULAR MOTION
1. TSW Draw a vector diagram to illustrate that the acceleration of a particle moving with constant
speed in a circle is directed towards the centre of the circle.
2. TSW Apply the expression for centripetal acceleration.
3. TSW Identify the force producing circular motion in various situations.
4. TSW Solve problems involving circular motion.
PROJECTILE MOTION (HL only)
5. TSW State the independence of the vertical and the horizontal components of velocity for a
projectile in a uniform field
6. TSW Describe and sketch the trajectory of projectile motion as parabolic in the absence of air
resistance
7. TSW Describe qualitatively the effect of air resistance on the trajectory of a projectile
8. TSW Solve problems on projectile motion
Suggested Materials:
Textbook, Syllabus, Data Booklet, PSOW form, Physics Core Investigations
IB Question Bank CD; topic Circular motion, Kinematics
LogerPro (Vernier software) and probes
Graphical Analysis software
Technology Resources:
PhET computer simulations: Ladybug revolution (for showing direction of centripetal acceleration),
Projectile-motion (great for virtual lab investigation!)
http://phet.colorado.edu/en/simulations/category/new
Online Curriculum Center: http://occ.ibo.org/ibis/occ/guest/home.cfm
Chris Hamper’s web page: http://www.rcnuwc.org/ibphysics/
Destiny and Web Path Express (available through your library)
Suggested internal assessment for the unit:
2 hours of IA or more
Physics Core Investigations (In the Suggested Resources folder); Investigation 7 – Uniform Circular
Motion;
The suggested PhET simulation, Projectile motion, is great for simple investigations. Use launchers if
you have them. Energy ramps can be adjusted for launching projectiles.
Suggested Instructional Strategies:
The students should be given examples of questions from previous IB exams.
Teachers should use questions and problems from the IB question bank.
Using the suggested PhET computer simulation(s) is strongly recommended.
A demonstration of natural phenomena is a great way to introduce a new topic.
Hands on activities in which students collect and analyze data are encouraged.
If you have launchers you should do an investigation with them. The projectile simulation is great for
investigation or just for fun. The IBO syllabus does not include anything on angular acceleration and
torques. Don’t emphasize these when teaching the unit.
Suggested assessment of mastery and beyond mastery of the unit:
It is strongly recommended that questions from past IB exams and from the IB question bank are used
for assessing mastery and beyond mastery.
Each TSW should be assessed with at least one question/problem. Some questions (for example
extended-response questions) can assess the mastery of more than one TSW.
B
To earn a B student will correctly answer
most questions that asses Lower Order
Thinking Skills (LOTS) and some questions
that assess Higher Order Thinking Skills
(HOTS).
SOME means at least a half
MOST means at least 70%
A
To earn an A student will correctly answer
most questions that asses Lower Order
Thinking Skills (LOTS) and most questions
that assess Higher Order Thinking Skills
(HOTS).
MOST mean at least 70%
For more detailed information on assessment of mastery and beyond mastery see the Suggested
Resources folder.