Physics Paper1 Qs

P1 1) Give 5 ways energy can be stored?

Chemical energy, kinetic energy, gravitational potential energy, elastic potential energy and thermal energy,

P1 2) What is chemical energy stores?

Energy transferred during chemical reactions. Stores include fuels, foods or chemicals found in batteries.

P1 3) What is kinetic energy stores?

Energy stored in an object because it is moving

P1 4) What is gravitational potential energy?

Energy stored in an object because of its position above the ground.

P1 5) What is elastic potential energy?

Energy stored in a springy object when you stretch or squash it.

P1 6) What is thermal energy?

A store of energy a substance has because of its temperature

P1 7) What are the energy changes in a torch lamp?

Chemical energy in battery à electric current in wires à energy transferred to surrounding (light and thermal)

P1 8) How can you represent energy changes?

Flow diagram

P1 9) What are the energy transfers in an object as it falls?

Gravitational potential energy store à kinetic energy store à energy transfer to the surroundings (thermal energy and sound waves)

P1 10) What is a system?

An object or group of objects

P1 11) What is a closed system?

A system in which no energy transfers take place our of or into the energy stores of the system.

P1 12) What is the principle of conservation of energy?

Energy cannot be destroyed or created.

P1 13) What is energy measured in?

Joules (J)

P1 14) What is work done?

Work is done on an object when a force makes the object move. Energy transferred = work done

P1 15) What is work done measured in?

Joules (J)

P1 16) How do you work out work done?

Work done, W (J) = force applied, F (N) x distance moved along the line of the force, s (m)

P1 17) What happens to work done to overcome friction?

Mainly transferred to thermal energy stores of the objects that rub together and to the surroundings.

P1 18) A builder pushed a wheelbarrow a distance of 5m across flat ground with a force of 50N. How much work was done by the builder?

250J

P1 19) What happens to the gravitational potential energy stores when an object moves up?

It increases

P1 20) What happens to the gravitational potential energy stores when an object moves down?

It decreases

P1 21) How do we calculate change in object's gravitational potential energy store with weight?

Change in object's gravitational potential (J) = weight (N) x change of height (m)

P1 22) How do we calculate change in object's gravitational potential energy store with mass?

Change of gravitational potential (J) = mass, m (kg) x gravitational field strength, g (N/Kg) x change of height (m)

P1 23) Why is it easier to lift objects on the moon?

Gravitational field strength of moon about a sixth of gravitational field strength on earth.

P1 24) A student of weight 300N climbs on a platform that is 1/2m higher than the floor. Calculate the increase in her gravitational potential energy store?

360J

P1 25) A 2kg object is raised through a heigh of 0.4m. Calculate the increase in the gravitational potential energy store of the object. The gravitational field strength of the Earth at its surface is 9.8N/kg.

7.8J

P1 26) What does the amount of energy in a kinetic energy store depend on?

Its mass and speed

P1 27) How do we work out kinetic energy?

Kinetic energy (J) =1/2 x mass (kg) x speed²

P1 28) How do you calculate the amount of energy in an elastic potential energy store?

Elastic potential energy (J) = ½ x spring constant (N/m) x extension²

P1 29) Calculate the kinetic energy stored in a vehicle of mass 500kg moving at a speed of 12m/s

36000J

P1 30) What is useful energy?

Energy transferred to where it is wanted in the way it is wanted

P1 31) What is wasted energy?

Energy that is not usefully transferred

P1 32) What is meant by energy dissipation?

Energy spreads out to surroundings

P1 33) What happens to the usefulness of energy as it dissipates?

Gets less

P1 34) What is input energy?

The energy supplied to an object/device

P1 35) What is useful output energy?

The energy that comes out that we actually want to use

P1 36) How do we work out efficiency?

Efficiency = useful output energy (J) / total input energy (J)

P1 37) A light bulb with an efficiency of 0.15 would radiate 15J of energy as light for every 100J energy supplied. What is its efficiency?

15%

P1 38) How do we reduce wasted energy by friction?

Lubricate moving parts to reduce friction

P1 39) How do we reduce wasted energy by resistance of a wire?

Use wires with as little resistance as possible

P1 40) How do we reduce wasted energy by air resistance?

Streamline shapes of moving objects

P1 41) How do we reduce wasted energy by sound?

Cut out noise, tighten loose parts to reduce vibration.

P1 42) What is the maximum energy efficiency something can be?

100%

P1 43) How is energy supplied to your home?

Electricity, gas and oil

P1 44) What is the useful and wasted energy of a light bulb?

Useful = light and wasted = thermal

P1 45) What is the useful and wasted energy of a toaster?

Useful = heating bread, wasted = heating toaster and air around it, lights.

P1 46) What are everyday uses of electrical appliances?

Heating, lighting, making objects move, producing sound and visual images.

P1 47) How would you choose an electrical appliance for a job?

Fit for purpose (does what you want) and wastes as little energy.

P1 48) What is meant by power?

The energy you supply to the motor per second (rate of energy transfer)

P1 49) The more powerful an appliance is....

the faster the rate at which it transfers energy

P1 50) What is power measured in?

Watts (W) or kilowatts (kW)

P1 51) How do we calculate power?

Power, P (W) = energy transferred to appliance (J) / time taken for energy to be transferred, t (s)

P1 52) What is the typical power rating of a torch and an electric cooker?

Torch = 1W, electric cooker = 10000W

P1 53) How do we calculate efficiency in terms of power?

Efficiency = useful power out / total power in x 100

P1 54) How do we calculate power wasted?

Power wasted = total power in - useful power out

P1 55) A motor transfers 10 000J of energy in 25s/ Work out its power.

400W

P1 56) The useful power out of an electric motor is 20W and the total power into it is 80W. What is its efficiency?

25%

P2 1) Which are better conductors: metals or non-metals?

Metals

P2 2) Which is a better conductor, copper or steel?

Copper

P2 3) The greater thermal conductivity....

The more energy per second it transfers by conduction.

P2 4) What is conduction?

Transfer of heat through a solid.

P2 5) What makes a good insulator?

A material that has low thermal conductivity

P2 6) How does the thickness of a material affect the rate of conduction through it?

Thicker material the slower the rate of conduction through it

P2 7) What is infrared radiation?

all objects emit and absorb infrared radiation

P2 8) The hotter the object, the more/less infrared radiation it emits in a given time?

more

P2 9) What is meant by black body radiation?

radiation emitted by a body that absorbs all the radiation incident on it

P2 10) What happens to the temperature of an object if it absorbs more radiation than it emits?

increases

P2 11) What happens to the temperature of an object f it absorbs more radiation than it emits?

increases

P2 12) How is the temperature of the Earth affected by the balance of absorbed and emitted radiation?

P2 13) What is specific heat capacity?

The energy needed to raise the temperature of 1kg of the substance by 1 degree Celsius.

P2 14) What is the equation fir specific heat capacity?

Energy transferred (J) = mass (kg) x specific heat capacity(J/kg/°C) x temperature change (°C)

P2 15) What is the unit for specific heat capacity?

J/kg °C

P2 16) How does the mass of a substance affect how quickly its temperature changes when heating?

The greater the mass of an object, the more slowly its temperature increases when it is heated.

P2 17) How can you reduce the amount of energy lost from your home?

Loft insulation, cavity wall insulation, aluminium foil between a radiator, double glazing windows, thicker walls.

P2 18) How does loft insulation lower the amount of energy lost from your home?

Reduces the rate of energy lost through the roof.

P2 19) How does cavity wall insulation lower the amount of energy lost from your home?

Reduces the rate of energy lost through the walls. It traps air in small pockets, reducing energy lost through conduction.

P2 20) How does aluminium foil between a radiation reduce the amount of energy lost from your home?

Reflects radiation away from the water, so reduces heat lost through radiation.

P2 21) How does double glazed windows reduce the amount of energy lost from your home?

Vacuum in between two glass panels prevents transfer of heat through conduction. Reduces amount of heat lost through windows.

P3 1) Where does most of our energy come from?

Burning fossil fuels

P3 2) How are most of our energy demands met?

31% coal, 4% nuclear, 7% hydroelectricity,, 24% gas, 31% oil and 3% other renewables.

P3 3) How do power stations produce energy?

Burning fuels heats water in a boiler. This produces steam. This drives a turbine that turns an electricity generator.

P3 4) What is a biofuel?

Any fuel taken from living or recently living organisms.

P3 5) Give 2 examples of biofuels.

Animal waste, methane gas

P3 6) Give 2 advantages of biofuels.

Renewable and carbon neutral

P3 7) What is nuclear fuel?

Takes energy from atoms.

P3 9) Give 3 types of renewable energy.

Wind, wave, hydroelectric, biofuel, tidal power, solar, geothermal

P3 10) How does wind generate electricity?

Wind turns a turbine . This turns a generator.

P3 11) How does wave power generate electricity?

A wave generator uses the waves to make a floating generator move up and down which generates electricity.

P3 12) How does hydroelectric power generate electricity?

Rain water collected in reservoir. This flows downhill, which drives turbines that turn electricity generators.

P3 13) How does tidal power produce electricity?

Traps water from each high tide behind a barrage. This is then released to turn turbines, which drives generators to produce electricity.

P3 14) What are solar cells?

Flat solid cells that use the Sun's energy to generate electricity directly.

P3 15) What are solar heating panels?

They heat water that flow through it using the energy from the sun.

P3 16) What is the difference between solar cells and solar heating panels?

Solar cells use the Sun's energy to generate electricity whereas solar heating panels use the Sun's energy to heat water flowing through it.

P3 17) What is geothermal energy?

Comes from the energy transferred by radioactive substances deep inside the Earth. The energy transferred from these heats the surrounding rock. Water pumped underground produces steam to drive turbines to generate electricity.

P3 18) What are 2 disadvantages of fossil fuels?

When burnt, greenhouse gases emitted into the atmosphere (most scientist believe these contribute global warming), non-renewable

P3 19) What are 2 advantages of nuclear power?

No greenhouse gases, much more energy transferred from each kg of uranium than from fossil fuels.

P3 20) What are 2 disadvantages from nuclear power?

Used fuel rods will contain radioactive waste - has to be stored safely, an explosion of a nuclear reactor could release radioactive material over a wide area.

P3 21) What are 3 advantages of renewable energy?

Never run out because they're always being replenished, do not produce greenhouse gases, do not create radioactive waste, can be used where use of national grid is economical.

P3 22) What are 3 disadvantages of wind turbines?

not able to meet world demands, create whining noise that can upset people nearby, some people consider unsightly, not available all the time

P3 23) What are 2 disadvantages of tidal barrages?

Not able to meet world demands, affect river estuaries and the habitats of creature and plants there.

P3 24) What are 3 disadvantages of hydroelectric power?

Not able to meet world demands, need large resovoirs which can affect nearby plant and animal life, not available all the time