Papper One Physics Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are the eight types of energy source

A

Thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, nuclear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a closed system

A

Where neither matter nor energy can enter or leave and the net change in total energy of a closed system is always zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does work done mean

A

Energy being transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a system

A

An object or group of objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

If an apple falls from a tree what is happening to transfer of energy

A

Energy is transferred from gravitational potential energy to kinetic energy store

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is kinetic energy

A

Energy store in moving objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the kinetic energy of stationery objects

A

Zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A car with a mass of 700kg is moving with a speed of 20 m/s. Calculate the kinetic energy for the car

A

Kinetic energy = 0.5 x mass x speed^2
Kinetic energy = 0.5 x 700 x 20 = 140,000 J
Kinetic energy = 140 KJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

A cyclist and bike have a total mass of 100Kg and a speed of 15 m/s. Calculate the kinetic energy.

A

Kinetic energy = 0.5 x m x v^2
Kinetic energy = 0.5 x 100 x 15^2=11250 J
Kinetic energy = 11.25 KJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A tennis ball is travelling at 50 m/s and has a kinetic energy of 75J. Calculate the mass of the tennis ball.

A

Kinetic energy = 0.5 x mass x speed^2
Mass = kinetic energy / 0.5 x speed^2
75/0.5 x50^2
Mass = 0.06 kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when you stretch a spring

A

We’re applying a force to change the length of the spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When you put energy into a spring to stretch it the stretch spring is storing this energy and we call that…

A

Elastic potential energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the relationship between extension(m) and force applied(N)

A

Directly proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is gravitational potential energy

A

Energy stored in an object due to it’s position above earth’s surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A crane lifts a 75kg mass a height of 8m. Calculate the gravitational potential energy gained by the mass. (Gravitational field strength = 9.8 N/kg)

A

Gravitational potential energy = mass x gravational field strength x height
GPE = 75 x 9.8 x 8 = 5880 J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A ball with a mass of 500g is lifted onto a shelf which is 1.5m above the ground. Calculate the gravitational field strength gained by the ball.

A

GPE = mass x height x GFS
GPE = 0.5 x 9.8 x 1.5
GPE = 7.35 J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Calculate the energy required to increase the temperature of 2kg of water from 20oc to 100oc. The specific heat capacity for water is 4200 j/kg 0c

A

Change in thermal energy = mass x specific heat capacity x temperature change
Change in thermal energy = 2 x 4200 x 80 = 67200
=672 kj

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

An iron has aluminium plate with a mass of 1.5kg. Calculate the thermal energy stored in the plate when the temperature rises from 20oc to 200oc. The specific heat capacity of aluminium is 913 J/kgoc

A

Change in thermal energy = mass x specific heat capacity x temperature change
Change in thermal energy = 1.5 x 913 x 180 =246510J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Kinetic energy definition

A

The energy stored in a moving object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gravitational potential energy definition

A

The energy stored due to an objects position above the ground.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Elastic potential energy definition

A

Energy stored in a stretched spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Thermal energy definition

A

Energy stored due to an objects temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the law of conservation of energy

A

Energy can be transferred usefully, stored or dissipated but it cannot be created or destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How can u reduce unwanted energy transfers

A

We can reduce unwanted energy transfers by reducing friction.
-use a lubricant e.g. oil on the fixed point
-remove air particles from around the pendulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When energy is transferred from one store to another…

A

Work is done

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does mechanical work involve

A

Using a force to move an object

27
Q

What does electrical work involve

A

Current transferring energy

28
Q

Energy is transferred between stores via ‘pathways’ , the four examples are:

A

Work done by a force(mechanical)
Work done by an electrical current(electrical)
Radiation
Heating

29
Q

During braking, a force of 2000 N is applied to the brakes of a car. The car takes 20m to come to a stop. Calculate the work done

A

Work done(J) = force(N) x distance(m)
Work done = 2000 x 20 =40,000 J

30
Q

Power definition

A

The rate at which energy is transferred or the rate at which work is done

31
Q

When a car stops, 40,000 J of work is done by the brakes in a time of 5 seconds. Calculate the power of the brakes

A

Power = work done(J)/time(s)
Power = 40,000/5=8000W

32
Q

A motor transfers 500 J of electrical energy into gravitational potential energy in 40s. What is its power?

A

Power = energy transferred/time = 500/40
Power = 12.5 W

33
Q

An electrical current delivers a power of 60 watts to a light bulb. 3 watts of electrical energy are transferred to light energy. Calculate the efficiency of the bulb.

A

Efficiency = useful power output/total power input
Efficiency = 3/60 = 0.05 x 100 = 5%

34
Q

Describe ways to increase the efficiency of an energy transfer

A

Reducing wasted energy

35
Q

Describe thermal conductivity

A

The higher the thermal conductivity of a material, the higher the rate of energy transfer by conduction across that material

36
Q

How can you reduce the thermal energy transfer from a house

A

Construct the building using materials with a low thermal conductivity. Build the house with thick walls as this also reduces the rate of thermal energy transfer

37
Q

What is specific heat capacity

A

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1kg of the substance by 1oc

38
Q

Required practical- specific heat capacity

A
  1. Place a beaker on a balance and press zero
  2. Now add the oil to the beaker and record the mass of the oil
    3.place a thermometer and an immersion heater into the oil
  3. Wrap the beaker in insulating foam to reduce thermal energy transfer to surroundings
    5.connect a joulemeter to the immersion heater
  4. Time for thirty minutes
  5. Read number of joules of energy that passed into the immersion heater
    8.record the final temperature of the oil
39
Q

0.95kg of oil was heated from 20oc to 75oc. 87258 J of electrical energy passed into the immersion heater. Calculate the specific heat capacity of the oil.

A

Specific heat capacity = change in thermal energy/mass x temperature change
Specific heat capacity = 87258/0.95 x 55 = 1670

40
Q

Sources of inaccuracy examples in the specific heat capacity practical

A

Thermal energy passing out of the beaker into the air
Not all thermal energy passing into the oil
Incorrect reading of thermometer
Thermal energy not being spread through the oil

41
Q

What are three uses of energy

A

Transport
Generating electricity
Heating

42
Q

Fossil fuel examples

A

Coal
Oil
Gas

43
Q

Fossil fuel advantages

A

They are reliable and always provide energy when we need it.
They also release a great deal of energy. They are abundant and relatively cheap.
They are extremely versatile

44
Q

Fossil fuel disadvantage

A

Burning fossil fuels releases a huge amount of carbon dioxide
Fossil fuels are non renewable. They are not being replenished as we use them
Burning fossil fuels can release other pollutants.
E.g. diesel-carbon dioxide particles and nitrogen oxides
E.g. coal-sulfur dioxide leads to acid rain

45
Q

What is nuclear power

A

Nuclear power is non reliable. Nuclear power plants run on the elements uranium and plutonium.

46
Q

Nuclear power advantages

A

Once a nuclear power plant is running It does not release any carbon dioxide, therefore nuclear power does not contribute to climate change.
Nuclear power is extremely reliable, it generates a lot of electricity exactly when we want it

47
Q

Nuclear power disadvantages

A

Nuclear power plants contain highly dangerous radioactive materials. If there’s an accident then these materials could be released into the environment.
Decommissioning a nuclear power plant takes many years and is extremely expensive
Nuclear power plants generates large amounts of highly dangerous radioactive waste. This must be stored for thousands of years before its safe

48
Q

What is coal used for in the 1900s

A

All heating and cooking in UK
Electricity came from burning coal

49
Q

Why did UK switch from coal to gas

A

Burning gas generates less carbon dioxide than burning coal. This contributes less to climate change.
Gas fired power stations are flexible. They can be switched on quickly during periods of high demand(short start up time). Coal-fired power stations have a very long start-up time

50
Q

Why did the UK switch from gas to renewables

A

In the 1970s, scientists began to realise that carbon dioxide emissions from human activity could be leading to climate change. At the politicians did not really see that as a big issue .
Energy from fossil fuels was very cheap. This is an economic factor. Switching away from fossil fuels costs money and that would cost jobs

51
Q

Renewable energy sources e.g.

A

Wind power
Solar power
Hydroelectric power
Geothermal
Wave power
Biofuels
Tidal power

52
Q

Advantages of renewable energy resources

A

Renewable energy resources will never run out
Once in place, renewable energy resources do not add any carbon dioxide to the atmosphere. They do not contribute to climate change

53
Q

Describe hydroelectric power

A

Hydroelectricity is only really useful in countries which have lots of rivers so it’s not really suitable for the UK

54
Q

Describe tidal power

A

Extremely reliable. At the moment, the UK does not generate any electricity from tidal power

55
Q

Describe wave power

A

Reliable and has huge potential in the UK which has an extensive coastline

56
Q

Drawback of tidal power

A

Some people believe its harmful to wild life

57
Q

Describe geothermal

A

Geothermal energy uses heat from the earth to generate electricity and heat buildings

58
Q

Petrol car compared to electric car

A

A lot of energy used in the UK is for transport, including cars. Almost all cars in the UK run on petrol or diesel which are fossil fuels.

59
Q

Describe biofuels

A

Biofuels are produced from plant materials. Burning biofuels does not add extra carbon dioxide to the atmosphere(carbon neutral)

60
Q

What is current

A

Flow of electric charge around a circuit

61
Q

What is the unit of electrical current

A

Ampere(A)

62
Q

How can we measure the current in a circuit

A

Ammeter

63
Q

How does Step up transformer efficient

A

Step up potential difference which means the current is lower and less energy is wasted as heat

64
Q

What does 1 volt of potential difference tell us

A

1 joule off energy is transferred for each coulomb of charge that is moving through the circuit