Flashcards
Physics 1
Flashcards do conjunto (36)
- 1What are the 3 ways heat is transferred ?Radiation , Conduction, Convection
- 2What can infra-red radiation travel through?Solids, Liquids and Gases
- 3What are the qualities of different colours based on radiation?Black - Absorb and emit radiation well
Light shiny surfaces - Reflect most of the radiation. - 4Kinetic theory explains 3 states being what ? How does it affect the state?Solids- Strong forces of attraction hold particles close together
Liquids- Weaker forces of attraction the particles are close but can move past each other.
Gas- Almost no forces of attraction and high amounts of energy. - 5Why are metals good conductors ?Metals conduct well due to the free electrons. Electrons move faster and collide with others to make the heat transfer down the solid.
- 6What types of matter can be convected ?Liquids and Gasses .
- 7What causes convection ?Convection occurs when more energetic particles move from the hotter region to the cooler region- and take their heat energy with them.
- 8What is the main factor of convection?Convection currents are all about changes in density. The more energy the particle has faster it moves away from other particles and the substances becomes less dense.
- 9What causes condensation ?A gas cools and the particles in the gas lose kinetic energy and therefore the attraction rises. If the temperature is cold enough the particles get close enough to make the gas a liquid.
- 10What factors will make the rate of evaporation higher ?Temperature- Higher the temperature the more particles have energy to escape.
Density- Lower density will mean lower forces of attraction.
Surface area- Larger more particles will be near enough to escape.
Airflow over liquid is greater to lower concentration in the air . - 11What is the equation for payback time ?Initial cost
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Annual saving - 12What types of heat transfer are involved in .. ?Cavity wall insulation - Reduce Convection and radiation through no open gaps, foam reduces conduction.
Loft insulation- Reduces conduction and radiation.
Draught Proofing- Reduces convection - 13What are U-Values and how do they work?A U-Value shows how fast heat can transfer through a material.
Heat travels faster through materials with high U-Values.
Better insulator , lower U-Value. - 14What does specific heat capacity tell us ?How much energy can be stored. Materials that use a lot of energy to heat up,also release a lot to cool down, they store lots of energy.
Specific heat capacity is the amount of energy needed to raise 1kg of a substance by 1*C - 15What is the specific heat capacity formulae?E=mXcX0
Energy(J)=mass(kg)X specific heat capacity (j/kg*C)X tempurature change (*C) - 16What are the 9 types of energy?Electrical
Light
Sound
Kinetic
Nuclear
Thermal
Gravitational Potential
Elastic Potential
Chemical - 17What is the conservation of energy principle ?Energy can be transferred usefully from one form to another, stored or dissipated. It can never be created or destroyed.
- 18How do you calculate efficiency?Useful energy out Useful power out
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Total energy in Total power in - 19What is the most common form energy lost?No device is 100% efficient and the wasted energy is most commonly lost in heat.
- 20How do you get Kilowatt-Hours ?Energy = Power X Time
A Kilowatt-hour is the amount of electrical energy used by a 1kW appliance left on for one hour. - 21How do you work out the cost of electricity ?Units = kW X Hours
Cost = Units X Price - 22Name the type of energy sources that are not renewable .Coal
Oil
Natural gas
Nuclear fuels - 23Name 5 of the renewable sources of energy .Wind
Waves
Tides
Hydroelectric
Solar
Geothermal
Biofuel - 24Why are energy sources burned to create electricity ?The fuel is burned to convert chemical energy in to heat. This is used to heat water and the steam will turn the turbine. This turns heat energy in to kinetic energy. The turbine is connected to a generator which turns kinetic energy to electrical energy.
- 25What must be considered whilst reviewing an energy resource ?Set-up cost
Reliability
Environmental issues
Set up/ Decommissioning time
Running cost
Location - 26Why is it less expensive to transfer energy in high voltage over current ?High current is less efficient as it produces heat energy which is lost in to the region around the wire. Therefore high voltage reduces the loss of energy which increases efficiency and decreases cost.
- 27Name the parts of a wave .
- 28What is a wave that travels sideways called with details ?A transverse wave. In Transverse waves the vibrations are perpendicular to the direction of the energy transfer in the wave.
- 29What type of wave is sound ?Sound travels in a longitudinal wave.
In a longitudinal wave the vibrations are parallel to the direction of energy transfer. of the wave . - 30What is the equation for wave speed ?Speed (m/s)=Frequency (Hz) X Wavelength (m)
- 31All waves can be _______,_______ and Diffracted.Reflected
Refracted - 32What are key features of reflection ?Angle of Incidence = Angle of reflection
Reflection of light allows us to see objects as light bounces off them in to our eyes. - 33How do you draw a ray diagram ?
- 34What do diffraction and refraction do to waves ?Diffraction - Waves bend around obstacles causing them to spread out.
Refraction - Waves go through the material but change direction. - 35What , in order , are the different types of wavesRadio waves
Micro Waves
Infra-red
Visible Light
Ultra Violet
X-Rays
Gamma Rays - 36How does the Doppler effect affect the sound of a moving car ?The car will sound love pitch as the wavelengths of the sound will be further apart. Therefore the pitch will be low.
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- FlashCards sobre Physics 1, criado por kinghanratty em 13-10-2015.
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