P2 Flashcards
What is the equation for GPE?
m x g x h
What is the equation for KE?
1/2 x m x (v)2
A 3000 kg helicopter
hovering at 20 m, what is its GPE?
3000 x 10 x 20 = 600,000J
What is bio-energy?
The power we produce from Biomass such as plants and animal matter.
Name 2 advantages and 2 disadvantages of Bio-energy
Advantages:
■ The fuel is cheap.
■ It helps get rid of waste, which can cause smells and pollution.
■ It is not using up limited resources like coal: biomass cannot run
out.
Disadvantages:
■ Burning the fuel creates carbon dioxide, a greenhouse gas.
However, if you grow crops that absorb the same amount of
carbon dioxide from the air that is created by burning them, the
effect on the environment is less harmful.
■ Collecting waste in big enough amounts to generate energy can
be difficult.
■ If trees aren’t grown especially for fuel, and re-planted, the result
is deforestation.
what is geothermal energy?
It is the energy extracted from the natural heat
that exists deep within the Earth.
Name to advantages and 2 disadvantages of geothermal energy
Advantages:
■ Geothermal energy doesn’t produce any pollution.
■ Running costs for a geothermal power station are very low.
Disadvantages
:■ It is difficult to find suitable sites for geothermal power stations.
The hot rocks have to be of a suitable type and depth, and the
rocks above them have to be soft enough to drill through. There
are hardly any sites in the UK.
■ If not carefully managed, a borehole can ‘run out of steam’ and
may not be useable again for several decades.
■ Occasionally, dangerous gases and minerals can come out of a
borehole, and it may be difficult to dispose of them.
what is hydroelectricity?
The extraction of energy from the energy in flowing water
Name to advantages and 2 disadvantages of hydroelectricity
Advantages:
■ No waste or pollution is produced.
■ Once construction is completed, operating costs are
very low.
■ Electricity can be generated constantly because water
can be stored and used as needed.
Disadvantages:
■ Dams are very expensive to build.
■ Hydroelectricity sites are often remote, which leads to
higher distribution costs.
■ Suitable sites for large-scale projects are hard to find.
what is solar energy?
Solar energy is energy
from the sun.
What is Passive solar design?
The design involves designing buildings to
make the most of the sun’s natural heat.
What is Active solar heating?
Water is pumped through pipes into solar panels (called
collectors) on the roof, and heated by the sun.
What is Photovoltaic cells?
They contain silicon, which
convert energy from the sun into electricity.
Name to advantages and 2 disadvantages of solar energy
Advantages:
■ Once the solar power plant is constructed, running
costs are very low.
■ Solar energy can be used to generate electricity in
remote places.
■ No waste or pollution is produced.
■ Energy is usually generated at or near where it will
be used, keeping transmission and distribution
costs to a minimum.
Disadvantages:
■ It doesn’t work at night.
■ Photovoltaic (PV) cells are very expensive (but they
are getting cheaper).
What is wind energy?
The energy extracted from the movement of warmer air rising and cooler air moving in to replace it. This movement of air is the wind.
Name to advantages and 2 disadvantages of wind energy
Advantages: ■ Once the wind turbine is built, running costs are very low. ■ No waste or pollution is produced. ■ The land occupied by a wind farm can still be used for farming. ■ Wind farms can become tourist attractions. Disadvantages: ■ No wind, no power. ■ Some people object because they feel wind farms spoil the view. ■ Wind farms create a constant low-level noise. ■ They can interfere with television reception and radar.
what is wave energy?
Energy extracted from the movement of the waves in the sea.
Name to advantages and 2 disadvantages of wave energy
Advantages:
■ Once constructed, running costs are very low.
■ No waste or pollution is produced.
■ Wave-energy generators are capable of producing
large amounts of energy.
Disadvantages:
■ Wave-energy generators are only effective where
they are exposed to strong waves.
■ They can be noisy.
■ Wave-energy generators may be a hazard to ships
and leisure craft.
what is tidal energy?
The energy extracted from the rising and falling of the sea
Name to advantages and 2 disadvantages of tidal energy
Advantages
■ Running costs are very low.
■ No waste or pollution is produced.
■ The technology is very reliable.
■ No fuel is required.
■ The amount of electricity and the time when it is produced is
totally predictable.
Disadvantages
■ There are only a few suitable places for tidal energy projects.
■ Tidal stream technology is at a very early stage of development.
■ Tidal schemes are expensive to install compared with other
renewable energies.
■ Damming bays or inlets can affect the environment over a large
area.
■ Barrage schemes will only provide energy for about 10 hours each
day, as the tide moves in and out.
What is the equation for efficiency?
Efficiency (%) = Useful Energy Out
—————————– x 100
Total Energy In
Calculate the efficiency of a runner who produces of 500J of kinetic energy from 2500J of chemical
energy.
20%
