Transcript Y10_P2_notes

Year 10 GCSE
Physics
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Living
for the Future
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LESSON 1 – Solar Power
LEARNING OUTCOMES:
• Describe some advantages and disadvantages of
using photocells to provide electricity:
• Describe how a photocell works and what affects
its power
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EXPERIMENT:
How does the area of a solar (photo) cell affect
the voltage it produces?
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CAN DO TASK (3):
How does the distance of a light from a solar
(photo) cell affect the voltage it produces?
Time = 20 minutes (results & analysis).
You must work on your own.
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LESSON 2 – Solar Heating & Wind Power
LEARNING OUTCOMES:
Describe other ways that the Sun’s energy can be
harnessed:
• how glass can be used to provide passive solar
heating for buildings;
• light reflected to a focus by a curved mirror;
• transfer KE of air to electricity in wind
turbines.
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LESSON 3 – AC & DC Generators
LEARNING OUTCOMES:
Recognise the differences between DC and AC and
illustrate them diagrammatically
Describe how simple generators work using the
dynamo effect .
Electromagnetic Induction
N
The ‘field
lines’ have
to be cut.
No current
is produced
if the
magnet is
not moving!
If You push a magnet into a coil the
electrons in the coil are also given a
push. This makes an ‘induced voltage’
Electromagnetic Induction
Notice the
needle
moves in the
opposite
direction
N
If You pull a magnet out of the coil the electrons
in the coil are once again given a push. This makes
an ‘induced voltage’ in the opposite direction
How Can You Increase the Size
of the Induced Current?
1. Move the Magnet Faster
2. Use a Stronger (not bigger!)
Magnet
3. Put more Turns on the Coil
We can use a magnet, coil and
movement to generate electricity
with this device
Will it make AC or DC Current?
This is a Generator
You will have heard them near road
works generating the electricity to
make the traffic lights and
machines work
AC Generator
Induced current can be increased
in 4 ways:
1) Increasing the speed of movement
2) Increasing the magnetic field strength
3) Increasing the number of turns on the
coil
4) Increasing the area of the coil
Bikes often have Dynamos to make
electricity to light a bulb
Dynamos are slightly
different from
generators as they
rotate the magnet
CAN DO TASK (3):
• Use the oscilloscope to measure the
frequency of the AC supply
• Time = 5 minutes (measurement &
calculation).
• You must work on your own.
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LESSON 4 – Power stations & Efficiency
LEARNING OUTCOMES:
Describe how the dynamo effect is used in
conventional power stations to generate electricity:
• burning fuel • producing steam • spinning a turbine
• turbine turns generator.
Be able to use equations to calculate efficiency in a
variety of situations.
Describe & recognise that there is significant
waste of energy in a conventional power station.
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LESSON 5 – Transformers
LEARNING OUTCOMES:
Explain how transformers are used on the National
grid to transmit electricity at high voltage to reduce
energy waste/costs.
Explain how, for a given power, increased voltage
reduces current. This will decrease energy waste by
reducing heating of cables.
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LESSON 6 – Fuels & Power
LEARNING OUTCOMES:
Describe that:
• burning fuels releases heat energy.
• uranium fuel rods release heat energy.
• fermenting biomass generates methane.
Calculate the power rating of an appliance:
power = voltage × current
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LESSON 7 – Electricity Bills
LEARNING OUTCOMES:
State that the unit of electrical supplied is the
kilowatt hour;
Calculate number of kilowatt hours given:
• power in kilowatts;
• time in hours;
Calculate the cost of energy supplied.
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LESSON 8 – Nuclear Power
LEARNING OUTCOMES:
Be aware that ionising radiations (from radioactive
waste) can cause cancer and that uranium is a nonrenewable resource.
Realise that plutonium is a waste product from
nuclear reactors and can be used to make nuclear
bombs.
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LESSON 9 – Radioactivity
LEARNING OUTCOMES:
Recognise that some materials release nuclear
radiation, and appreciate that there are 3 main
types – Alpha, Beta and Gamma.
Be able to describe the properties and uses of
Alpha, Beta, Gamma radiation.
Be aware that we are surrounded by several
sources of background radiation.
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LESSON 10 – Ionization & safety
LEARNING OUTCOMES:
Be able to explain ionization in terms of electron
behaviour.
Be aware of safety issues involving use of
radioactive materials, including methods and
hazards involved in disposal of waste products.
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LESSON 11 – Aurora & Magnetic Fields
LEARNING OUTCOMES:
Recognise the shapes of magnetic fields around the
Earth.
Be aware of the phenomena of Aurora and what
causes them.
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MAGNETIC FIELD OF A COIL
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MAGNETIC FIELD OF THE EARTH
What is the SOLAR WIND?
The solar wind is a flow of electrically
charged particles (protons and electrons)
streaming out from the Sun’s corona. They
travels at speeds of 400km/s to 850 km/s.
What are AURORA?
When the solar wind reaches the Earth, it
interacts with our magnetic field. Changes
in the solar wind cause changes the shape
of the Earth’s magnetic field and electrons
get accelerated towards the atmosphere
above the N and S pole. They cause
atoms in the air to emit erie glowing
lightwaves.
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Click for Aurora movie:
Click to ‘hear’ Aurora:
Aurora Borealis TASK:
Make a poster describing what the aurora are and
what causes them.
See p 200 of Gateway Science.
Include the following key points:
•Cosmic rays – fast charged particles which create
gamma rays
•Deflected by magnetic field. Spiral in to poles
•Excite atoms and make them glow
•Gives off gamma rays when cosmic rays hit atoms.
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LESSON 12 – Solar Flares & Magnetic
Fields
LEARNING OUTCOMES:
Know that magnetic fields can be generated by
moving electrical particles.
Appreciate that solar flares create problems on
Earth, caused by charged particles interacting with
the Earth’s magnetic field.
What are SOLAR FLARES?
When the solar wind reaches the Earth, it
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LESSON 13 – Earth & Moon
LEARNING OUTCOMES:
Be aware of evidence for the formation of the EarthMoon system.
Be able to compare objectively different ideas for
how it occurred.
Understand the size and positions of common
objects in space.
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LESSON 14 – Solar System
LEARNING OUTCOMES:
Understand the size and positions of common
objects in space.
Appreciate that objects moving in orbits require a
centripetal force, provided by gravity
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LESSON 15 – Space Missions
LEARNING OUTCOMES:
Appreciate the problems involved in manned space
missions and the advantages of using unmanned
space probes.
State that unmanned spacecraft can send back
information on:
• temperature, magnetic & radiation;
• gravity, atmosphere and surroundings.
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LESSON 16 – Asteroids & Craters
LEARNING OUTCOMES:
Know that a near-Earth object (NEO) is an asteroid
or comet on a possible collision course
with Earth.
Work as part of a group to exchange & discuss
ideas and present strategies to reduce the dangers
posed by NES.
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LESSON 17 – Comets & NEO
LEARNING OUTCOMES:
Know that a near-Earth object (NEO) is an asteroid
or comet on a possible collision course
with Earth.
Work as part of a group to exchange & discuss
ideas and present strategies to reduce the dangers
posed by NES.
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Ideas to prevent NEO impacts:
•
•
•
•
Gravitational tractor
Missiles
Early detection
Attach engines?
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LESSON 18 – Life Cycle of Stars
LEARNING OUTCOMES:
Recognise that stars have life cycles and many of
the early stages are common to all masses of stars.
Describe the end of a medium-weight star like our
Sun:
• red giant • planetary nebula • white dwarf;
Describe the end of a heavy-weight star:
• red giant • supernova • neutron star or black hole.
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LESSON 19 – Big Bang Theory
LEARNING OUTCOMES:
Be aware of the observations that the universe is
expanding and understand how the Big Bang model
accounts for this.
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LESSON 20 – TEST