02.1 - Kinematics

Kinematics

Uniform Acceleration

02.1 - Kinematics

Constant Velocity Model

Uniform Acceleration Model

Motion in Action

02.2 - Forces

02.3 - Work, Energy, Power

02.4 - Momentum and Impulse

Enduring Understandings:

The ideas of motion are fundamental to many areas of physics, providing a link to the consideration of forces and their implication. The kinematic equations for uniform acceleration were developed through careful observations of the natural world. (1.8) (IB)
All motion is relative, everything moves, nothing is ‘at rest.’
- Everything moves – atoms and molecules; the stars, planets, and moons; the earth and its surface and everything on its surface; all living things, and every part of living things. Nothing in the universe is at rest.
- Since everything is moving, there is no fixed reference point against which the motion of things can be described. All motion is relative to whatever point or object we choose. … There is no point in space that can serve as a reference point for what is actually moving. (Science For All Americans, p 47)
Movement within systems is defined by a set of established rules.
Motion may be described and analysed by the use of graphs and equations.

2.1 – Motion

Nature of science:
- - Observations: The ideas of motion are fundamental to many areas of physics, providing a link to the consideration of forces and their implication. The kinematic equations for uniform acceleration were developed through careful observations of the natural world.

Understandings:

Distance and displacement
Speed and velocity
Acceleration
Graphs describing motion
Equations of motion for uniform acceleration
Projectile motion
Fluid resistance and terminal speed

Applications and skills:

Determining instantaneous and average values for velocity, speed and acceleration
Solving problems using equations of motion for uniform acceleration
Sketching and interpreting motion graphs
Determining the acceleration of free-fall experimentally
Analysing projectile motion, including the resolution of vertical and horizontal components of acceleration, velocity and displacement
Qualitatively describing the effect of fluid resistance on falling objects or projectiles, including reaching terminal speed

Guidance:

Calculations will be restricted to those neglecting air resistance
Projectile motion will only involve problems using a constant value of g close to the surface of the Earth
The equation of the path of a projectile will not be required

International-mindedness:

International cooperation is needed for tracking shipping, land-based transport, aircraft and objects in space

Theory of knowledge:

The independence of horizontal and vertical motion in projectile motion seems to be counter-intuitive. How do scientists work around their intuitions? How do scientists make use of their intuitions?

Utilization:

Diving, parachuting and similar activities where fluid resistance affects motion
The accurate use of ballistics requires careful analysis
Biomechanics (see Sports, exercise and health science SL sub-topic 4.3)
Quadratic functions (see Mathematics HL sub-topic 2.6; Mathematics SL sub-topic 2.4; Mathematical studies SL sub-topic 6.3)
The kinematic equations are treated in calculus form in Mathematics HL sub-topic 6.6 and Mathematics SL sub-topic 6.6

Aims:

Aim 2: much of the development of classical physics has been built on the advances in kinematics
Aim 6: experiments, including use of data logging, could include (but are not limited to): determination of g, estimating speed using travel timetables, analysing projectile motion, and investigating motion through a fluid
Aim 7: technology has allowed for more accurate and precise measurements of motion, including video analysis of real-life projectiles and modelling/simulations of terminal velocity

Important Misconceptions to Consider / Overcome

Students don't readily differentiate between position, velocity, and acceleration.They have a single, undifferentiated idea of "motion."

Position and velocity are sometimes confused. If car B overtakes and passes car A on the freeway, both traveling in the same direction, many students will say the cars have the same speed at the instant when B is alongside A.

Velocity and acceleration are frequently confused. When asked to draw velocity and acceleration vectors, students often draw acceleration vectors that mimic the velocity vectors. At a turning point (end of a pendulum's swing, top of the motion of a ball tossed straight up, etc.), nearly all students will insist that the acceleration is zero. This is an especially difficult belief to change.

Acceleration is associated only with speeding up and slowing down. Very few students associate acceleration with curvilinear motion. This is not surprising, because a vector acceleration as we use it in physics is a definition, not a common sense observation. Many students, from high school physics, may know that circular motion has a centripetal acceleration. But this is a memorized fact; almost none can tell you why the acceleration points to the center.

Students interpret a positive acceleration as always meaning "speeding up" and a negative accelerating as "slowing down," rather than associating the sign with the direction of the acceleration vector. This is a difficult idea to change, and for many students it becomes a serious difficulty when they get to Newton's second law.

General Resources for Motion

One Dimension Motion - A playlist of videos all related to the Motion Topic. (31 Videos You do NOT need to watch all of them.)

Online Resources

02.1 - Motion: Please open this document to see all of the required info for this sub-topic.

The Big Four Equations

Core Understanding Notes:

From any of the resources below, include the following core understandings.

Vocabulary: define and have working understandings of the following terms

Displacement
Distance
Velocity
Acceleration
Speed, faster, slower (speed up, slow down)
Instant, Instantaneous
Relative velocity
Average velocity, speed, acceleration
SUVAT
Free fall

Core Knowledge: Having a working understanding of these ideas will aide in your understandings in class discussions.

Compare the following pairs:
- Distance v Displacement
- Speed v Velocity
- Vector v Scalar
- Velocity v Acceleration
- Instantaneous v Average
Outline the conditions under which the equations for uniformly accelerated motion may be applied.
Identify the acceleration of a body falling in a vacuum near the Earth’s surface with the acceleration g of free fall.
Identify important aspects/characteristics of Position v. Time, Velocity v. Time and Acceleration v. Time graphs. (1. Points, 2. Slopes/Gradients, 3. Area Under the Curve)

Describing Basic Motion - CV / AM Models

Kinematics Vocab

Applications and skills:

- - Determining instantaneous and average values for velocity, speed and acceleration
  - Sketching and interpreting motion graphs

Text Resources:

The meaning of position - time graphs (3 sections) - PhysicsClassroom.
The meaning of velocity-time graphs (5 sections)- PhysicsClassroom.

Video Resources:

Please use these resources for your notes, if you have further questions please do not hesitate to ask.

Vi Hart Videos:
Walking Graphs - Long but excellent description of relationship amongst graphs.

Problems:

You can print out the worksheets (wkst) or answer them within your notebook.

Average Speed Ranking (wkst)
Constant Velocity Concept Q's (wkst)
Matching the motion to the graph (simulation)
Ramps and Graphs (a good challenge) (simulation)

Graphing Questionnaire
Motion on a Ramp - In class data collection
Motion in Action
IB Exam WB's (Paper 1 Q's)

Below this are simply thoughts and possible ideas nothing is expected from below this line:

Activities: (To Be Determined 2020)

Linear Motion Formative
Accelerating in relation to gravity - How many g's?
- Angle of Ramp
- Ball Toss - Using your phone's camera and LoggerPro's video analysis, determine the acceleration of gravity from a thrown ball.
Stump the chump graph challenges
- Draw a single graph, challenge your friends to draw the complimentary graphs.
Creating meaning from graphs - the SUVAT eq's

Formative Questionnaires:

Parabolic (2D) Motion

Airdrop - Performance Assessment

Can you hit the target?

Moving target and falling ball.

Determine variables,

Possible to create comp program to determine drop point? Automate with MicroBits?

Distance and displacement

Speed and velocity
Acceleration
Graphs describing motion
Equations of motion for uniform acceleration
Projectile motion
Fluid resistance and terminal speed

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