Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Science > Energy(p) > Flashcards

Energy(p) Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Is energy created?

A

No it is not created or destroyed.
But transferred

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

What are the energy stores?(7!!?)

A

-thermal (heat)
-kinetic (motion)
-gravitational potential (position of gravity)
-elastic (stretched spring)
-magnetic
-electrostatic
-nuclear ( breaks atom)
-chemical (hold bonds)

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

How do you transfer energy? (4)

A

•Mechanically
•heating
•electrically
•radiation
•light
•sound

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

What is a system???£?

A

A collection of matter

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

What is the difference between an open and closed system?(:

A

Open system: let’s energy be transferred to the outside world( (loses/gain energy via outside)

Closed system: energy not transferred to outside world[ overal zero change]

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

What is work done (2 things ⚙️⚡️?)

A

Mechanical: force moved in object

Electrical: current flows energy. Needed to overcome resistance in wire

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

What is kinetic energy??

A

Energy it’s posses due to its motion
-more faster mean more kinetic energy
-more mass mean it has not kinetic energy (hence affected by mass and speed)

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

What is the equation for kinetic energy?

A

E(small k) = 1/2 mv (squared)

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

What is Definition of gravity?

A

A force of attraction between two objects

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

What is gravitational field?

A

‘Gravitational field strength’

Has strong forces of attraction

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

What is gravitational field of earth and moon?

A

Earth 9.8
Moon 1.6

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

What is the weight (and equation?)

A

The force acting in a gravitational field

Mass x gravitational field strength

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

What is the formula for gravitational potential energy?

A

E(small p)= mgh

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

H

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

What is internal energy?

A

The total energy stored by the particles making up a substance/system

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

What is kinetic energy stores?

A

The movement energy of the particles
(

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

What happens when you heat up kinetic energy stores?

A

The internal energy increases. Which then can be used to measure the temperature increase

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

What is temperature?

A

Measure of Average internal energy of a substance.

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

What is specific heat capacity?

A

The amount of energy needed to raise the temperatures of 1kg of a substance by 1C

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

What happens to energy when substance cools down?

A

Substance releases energy

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

What is the formula which includes change in internal energy, mass, specific heat capacity, temperature change?

A

Change in internal energy= mass x specific heat capacity x temp. Change

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

What happens when energy is ‘dissipated’?

A

It is lost to its surroundings

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

What is conduction in terms of particles?

A

Vibrating particles that transfer energy to neighboring particles. (Occurs in a solid)

so lots of collisions happen

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

What is thermal conductivity?

A

How well objects transfer energy by conduction

(Metals have high TC, plastic and fluids have low TC)

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

What is convection m?

A

Where particles move to gain kinetic energy

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

What is raidiation?

A

heat energy transferred without particles, carried by infrared waves

[The hotter the objects, the more radiation!]

27
Q

What is a fluid?

A

A substance in which particles are free to move around- include liquid and gas

28
Q

What is a convection?

A

When heat is transferred through liquids and gassed

29
Q

What is conduction?

A

When heat is lost directly through a solid

30
Q

What are the two method to reduce unwanted energy transfers?

A

-thermal institution
-lubrication

31
Q

How are homes insulated to keep heat?

A

• have foam seals
• walls
• window
•thick walls
•cavity walls
•double glazing windows

32
Q

What are cavity walls?

A

2 walls which have insulating foam between them. Which has pockets of air. As air is a good heat insulator

33
Q

What are double glazing windows?

A

Two glass layers that have an air gap in between. To reduce not only convection, but conduction

34
Q

Why do we reduce friction to reduce unwanted energy transfers?

A

As friction reduces the EFFICIENCY of energy transfer

35
Q

What methods are there to reduce friction?

A

-oil added on cogs to make it easier to peddle

-vehicles are streamlined to reduce friction from air resistance. Allowing less fuel to be used

36
Q

What is power?

A

The rate at which energy is transferred/ work is done

P=E/T
P=W/T

37
Q

What is work done?

A

When force is used to move object by certain distance

38
Q

Does energy transfer need force?

A

No, it does not need force or movement

39
Q

What are the measurement for power,energy/work done and time?

A

Power is watts
Energy is Joules
Time is seconds

40
Q

What is efficiency?

A

Proportion of energy supplied to the useful energy output

41
Q

What is the equation for efficiency?

A

Efficiency = useful energy output/ total energy input

Or

Efficiency = useful power input/ total power input

Can be calculated to either: decimal or percentage

42
Q

What are renewable resources?

A

Infinite resources.
-solar
-wind
-Hydroelectric
-tidal
-geothermal
-biofuel

43
Q

What are non-renewable resources?

A

Finite resources
-natural gasses
-coal
-oil
-nuclear

44
Q

What is energy used for? In life

A

Transport: cars, Planes and trains (Cole, electricity and biofuel)

Domestic: cooking and heating ( coal, natural gas, solar and biofuels)

45
Q

what are fossil fuels

A

hydrocarbons from remains of dead plants and animals

46
Q

3 examples of hydrocarbons

A

coal, crude oil, natural gas

47
Q

when fossil fuels are burnt, what do they provide?

A

-energy used for direct use, (cooking
-power for engines
-generate electricity

48
Q

what are pros of fossil fuels for energy?

A

cheap
can be used in any condition
there is lots of infrastructure designed to run on fossil fuels

49
Q

what are cons of using fossil fuels for energy?

A

is a limited resource
produces carbon dioxide when burned
sometimes produce toxic gases when burned

50
Q

what is nuclear energy?

A

energy obtained by nuclear reactions (nuclear fusion reaction)

51
Q

what does nuclear energy provide?

A

electricity that can be transmitted to homes and factories

52
Q

what are the pros of using nuclear energy?

A

doesn’t release pollutants, can be used in any condition, it is very unlikely to run out

53
Q

what are the cons of using nuclear energy?

A

it is a finites resource, produces radioactive waste that harms organisms, expensive, and there is a small chance of a nuclear meltdown=more waste

54
Q

how do you produce wind energy?

A

via turbines, which are placed in strong winds, so the wind can spin the blades, producing kinetic energy, moving the generator, that then produces electrical energy for national grid

55
Q

how do you produce solar energy?

A

using solar cells, which generate electrical currents directly from sunlight, which is useful in remote regions

56
Q

what are the pros of wind and solar energy?

A

-has low running costs
-doesn’t produce pollutants
-is environmentally friendly

57
Q

what are the cons of wind and solar energy?

A

-has high production cost=pollution via production
-dependent on weather
-requires large areas, as there needs to be lots of wind turbines and solar cells to produce large amounts of energy

58
Q

What are the two hydroelectricity machinery and what do they do?

A

-Hydroelectric dams: trap water that comes from upstream, into reservoir, making dam full of water
-tidal barrages: making use of tides so water is trapped on one side of dam(one get high)

These are due to Effectc of moon gravity on tides ,cause rise=high tides and fall=low tides

59
Q

How does hydroelectric produce electricity?

A

-different water levels cause huge amount of gravitational potential energy to be turned into electricity

-the from water levels changing. Turbines spin in the dam producing kinetic energy converted to motor into electrical energy

60
Q

What are pros and cons and hydroelectricity?

A

Pros:
-low running cost
-reliable source
-no pollution
-renewable
Cons:
-big impact on environment
-initial purchase is expensive

61
Q

What is momentum?

A

Mass x velocity

62
Q

What does the conservation of mass state?

A

States that in a closed system the total momentum before=total momentum after event

-also after collision particle is treated as a single large particle

63
Q

How much momentum do objects have

A

0

Science (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions