Download SAC: Solution to a scientific or technological problem

SAC: Solution to a scientific or technological problem
Note: These are theoretical, research-based activities, not practical ones. The construction of models or
prototypes are not required. The product only requires text and drawings and can be submitted in
written form, orally or in an audiovisual format. Students are not expected to include physics concept
beyond the course.
AOS 1: How do things move without contact?
SAC: Separation of particles
Description: Your challenge is to come up with a design for a device that separates particles according to
their mass and type using electric, magnetic and gravitational fields.
You can assume that the first step of your device is to pass your particles through a "rubbing machine",
where they will acquire a small charge due to tribo-friction. When different materials rub against each
other, they often gain a small charge due to the differences in electro-negativity of the materials.
Electro-negativity is an intrinsic property of a material.
You will need to consider:
 how do electric, magnetic and gravitational fields influence the motion of charged particles
 what size and mass range of particles is your device going to be suited to
 what types of materials your device is suited to
 what will be your sources of electric and magnetic fields
 what will the fields experienced by your particles look like?
 what are the limitations of your device
Your report on your proposed device needs to qualitatively and quantitatively address the above points.
5
4
3
Qualitative knowledge of fields and
interactions
Quantitative knowledge of fields and
interactions
Qualitative knowledge of effects of
fields
Quantitative knowledge of effects of
fields
Qualitative application of field
concepts
Quantitative application of field
concepts
Communication and expression of
science ideas - terminology
Communication and expression of
science ideas -clarity and referencing
Vicphysics Teachers' Network: www.vicphysics.org
2
1
0
SAC: Reduction of friction
Description: Friction is a considerable source of inefficiency in mechanical systems. Design a device
that uses electric and magnetic fields to create frictionless components.
You will need to consider:
 how do electric, magnetic and gravitational fields influence the motion of the components in your
device
 what size and mass range of components are suitable in your device
 what will be your sources of electric and magnetic fields
 the size, shape and magnitude of the fields experienced by your particles look like
 the limitations of your device
Assessment grid as above
AOS 2 How are fields used to move electrical energy?
SAC: - Harnessing the Earth's magnetic field in space (this topic overlaps AOS 1, which could be a
problem. Author's note)
Description: Objects orbiting the Earth experience the Earth's magnetic field. Can that magnetic field be
used to generate electricity? Faraday's Law suggests that it is theoretically possible. Design a device that
will deliver electrical power to a space-station or satellite by harnessing the Earth's magnetic field.
You need to consider the following:
 The shape and strength of the magnetic field experienced by an object orbiting the earth
 The possibilities for inducing EMF Forces acting on the objects.
 The magnitude and nature of the current resulting from your design.
 Possible uses of the electricity generated.
Your report on your proposed device should qualitatively and quantitatively address the above points.
Assessment criteria:
5
4
3
2
1
0
Qualitative demonstration of
knowledge of effect of fields
Qualitative demonstration of
knowledge of generation of electricity
Quantitative demonstration of
knowledge of effect of fields
Quantitative demonstration of
knowledge of generation of electricity
Communication and expression of
science ideas - terminology
Communication and expression of
science ideas - clarity and referencing
AOS 2: How are fields used to move electrical energy
SAC: Optimising magnetic field design
Description: Modern flexible fridge magnets are made from magnetic materials arranged in an ingenious
way so that they are strongly magnetic on one side only. Consider devices, such as the DC motor or AC
alternator which rely on magnetic field for operation. How are such devices limited by the use of
conventional electromagnetic and bar magnet technology? Could their function be improved by the use
of designer fields created by novel magnetic materials?
(Not sure whether this works, but fridge magnets are very interesting: Author's note)
Vicphysics Teachers' Network: www.vicphysics.org
SAC: harnessing bioelectric fields
Description: Many organisms, such as electric eels, are classified as electrogenic because they are able
to generate an electric field. Select an electrogenic organism and design a solution allowing us to exploit
the electric field to generate electricity.
You will need to consider:
 the magnitude and shape of the electric field of the organism • how the field can be used to generate
current in a circuit
 the magnitude and nature of the current
 accompanying magnetic effects
 possible uses of the electricity
Assessment: see grid above
AOS3 : How fast can things go?
SAC: Road engineering
Description: Consider the design of a road through a range of hills, that follows the topography of the
hills. As an engineer, you want to optimise the road so that it is as safe as possible over a range of
conditions, but allows drivers to travel as close as possible to 80kmh'.
Consider a particular corner, with an effective radius of 50m. How will you design the road surface to
optimise the safe speed for wet and dry weather. What will be your recommended speed limit?
Problem with this choice is that it doesn 't relate to special rel or energy transformations. Could add
something about power use and make the corners change height. Author's note
SAC: controlling distant probes
Description: We have launched many investigative probes from Earth to explore our universe. How can
we alter the trajectory of such probes after launch? How does special relativity affect our interpretation
of signals sent back by the probes and signals that we send to the probes?
5
4
3
Qualitative knowledge of Newton’s Laws of
motion
Quantitative knowledge of Newton’s Laws of
Motion
Qualitative knowledge of Einstein’s theory of
special relativity
Quantitative knowledge of Einstein’s theory of
special relativity
Qualitative knowledge of relationships
between force energy and mass
Qualitative knowledge of relationships
between force, energy and mass
Communication and expression of science
ideas - terminology
Communication and expression of science
ideas - clarity and referencing
Vicphysics Teachers' Network: www.vicphysics.org
2
1
0