Physics Support for Islington Schools
An INSET session was held in the physics laboratory at
City and Islington (map)
on 1st February 2011 at 4pm looking at practical ways of teaching
some of the physics topics at GCSE.
We started with some written materials looking at pupils misconceptions.
We then talked about the physics of the activities in the room before trying them out.
We looked at some larger demonstartionsl and finished up with a discussion of the issues and questions of using these activities in class.
Forces and motion:
Measuring average speed
We measuring the average speed of a toy car using stopwatch and rule.
The car was pulled by some fishing line attached to the car.
The force to move the car was supplied by paper clips on card hanging off the end of bench.
It is worth having a discussion about average speed and the instantaneous speed of the car at the start and end of the run.
You can get a nice graph of average speed against number of paper clips and relate this to Newton's second law
(a force produces a change in momentum; big force, big change in momentum).
Acceleration can be measured by measuring the average speed over two distances but this is quite tricky.
We attached fishing line to the ceiling and held it taught with some masses hanging off the end.
A piece of straw was taped to a balloon to guide it up the fishing line.
The challenge was to lift the most paper clips 1 metre off the ground.
This can be related to Newton's third law: the balloon is pushing the air down out of the neck so the air is pushing the balloon up with the same force.
Measuring forces in with dynamometers
We did a some simple practical with two Newton meters to show that when pulling the force acting on the puller is always the same as the force acting on the pulled.
We tried hanging masses and pulling two people pulling each other using a string with a dynamometer at each end and related this to Newton's third law.
We then challenged pupils perception that this only works when forces are balanced by repeating the experiment when pulling someone on a wheels (sitting in an office chair).
Pendulum and wine glass
A heavy pendulum was suspended near a wine glass. The pendulum was pulled so that it just touched the wine glass.
When the pendulum is released it swung back to just touch the glass again but did not knock it over.
We discussed the forces acting on the pendulum at various points in its path and its motion.
We then had a discussion of the energy of the pendulum.
Motion sensor and datalogging
We used a datalogger to produce distance time graphs of a person walking.
We drew a distance time graph on the board and then tried to walk to reproduce the graph on the datalogger.
Guinea and feather demonstation
We looked at the classic guinea and feather experiment where a coin and feather or piece of paper is dropped in a vaccuum to show that all things fall at the same rate without air resistance.
We also watched a video of Apollo 15 astronauts doing this on the moon with a hammer and feather.
Van de Graaff generator
We used the
Van de Graaff generator to do a variety of standard demonstrations including lighting a fluorescent tube.
We gave balloons a charge by rubbing them and then showed that they repel each other.
We had a look at radioactivity from everyday objects by using a geiger tube and counter to measure the activity of the source.
We analysed the form of activity by using absorbers to see what is needed to reduce the count.
We measured the activity of LoSalt which contain lots of potassium
(0.0117% of potassium is the radioactive isotope K40).
We looked at the activity of vaseline glass which contains uranium to colour the glass and a piece of granite worktop which contains about 0.001% uranium.
We discussed the radioactivity of the human body
and compared the radioactivity of a class of pupils with a school radioactive source (185kBq).
We used some models of radioactive half-life. Half-life can be modelled with pasta by putting pasta on a tray all laid the the same way.
The pasta is the disturbed by dropping the tray conatining the pasta and removing, counting and recording the number of pieces of pasta that are on their side.
The process is repeated several times and a graph drawn. The students estimate the half-life and compare their results.
Possible worksheet here.
We made an infra-red sensor using a phototransistor ansd LED. We then used an infra-red LED and a remote control to investigate the properties of IR.
Pinhole camera demonstration
We looked at a demonstration of the pinhole cmera using coloured light bulbs on the floor and a large newsapaper with a hole torn in the middle to produce an image of the bulbdbs on the ceiling.
We made a camera obscura from a lens, tracing paper nd cardboard.
We looked at the path of light through a lens using lasers and a smoke machine to scatter the laser light. We also looked at
computer simulations of light rays through a lens.
Some links for some ideas for practicals.
The Institute of Physics provides good support for physics teaching
and has excellent physics teaching resources available online.
There is superb support through the TalkPhysics.org
website which has discussion forums and free resources available to teachers but you need to register first.
Schools should seriously consider
affiliating to the Institute of Physics.
Details of common experiments can be found at the
Practical Physics website
with useful hints on how to get things to work well.
This website also has some good ideas for simple practicals using cheap household items:
The naked scientists.
The planet-scicast website shows loads of video clips for science. This one shows the
making of a wave machine:
This website is full of classic physics demonstrations: most of them
take a bit of setting up but are worth doing.
I would not do the bowling ball pendulum for health and safety reasons,
it is ok for a big demo where you have lots of control but not the
classroom - if someone pushes the ball or the pupil moves forward they
end up with a broken nose.
This website does not have practicals but it does have some good
resources and is a good source of info for teachers.
Most of the teachers should be aware of the practicalphysics.orgwebsite.
Most of the practicals are standard text book stuff, but the details of how to get things working are good.