Physics

Define eficiency

The amount of useful output of energy that a system uses from its total energy input.

What is a closed system

A system that does not allow energy in or out of the system.

What is an open system

A system that allows energy in or out of the system.

What is wasted energy (dissipated energy)?

Energy transferred in a not useful way, typically to the surroundings as thermal energy.

Define dissipation

When energy that is not useful to an object, is transferred to the surroundings as thermal energy.

Define an energy source

A supply of energy, that can be used to achieve demand

What is renewable energy?

Energy that can be replenished as it is used (e.g wind, solar power or hydroelectric).

Describe what non-renewable energy is?

A resource of energy that is finite, therefore cannot be replenished as it is used.

State the advantages of nuclear power energy sourcing:

Infrastructure is already built. It is very cost efficient. It is easy to run due to resources needed being easy to aquire.

State the disadvantages of nuclear power stations energy sorecing?

Releases nuclear waste (bad for human health and wildlife), dangerous for employees to run, release toxic fumes.

Define desity

Density is the mass per unit of volume.

State the word equation to density

Density = Mass / Volume.

What is the word equation to work done?

Work done = Force (Newtons) x distance (meters).

What is the word equation for kinetic energy

Kinetic energy = 0.5 x mass (kg) x velocity squared.

What is gravitational potential energy?

Energy gained by an object when it has potential of be overcome by the force of gravity.

What is the word equation to elastic potential energy

Elastic potential energy = 0.5 x spring constant x extension²

State the word equation to efficiency

Efficiency = Useful output of energy / Total input of energy.

Define energy dissipation

Energy that is transferred out of a system not usefully, therefore is wasted energy.

Explain conduction

A type of heat transfiguraion, when heat energy is transferred through particles to heat (typically) solid. This is done by a heat source transferring energy to particles as heat energy- this is transferred to the kinetic energy stores of the particles. The vibration of the particles increase, which causes them to collide with other neighbouring particles. This then makes the heat energy transfer to the neighbouring particles, in the same way it did between the heat source and the beginning particle.

Define convection

Heat transfiguration that occurs due to the physical movement of particles.

Explain a convection current.

A type of heat transfiguration that mainly occurs in fluids (liquids and gases), it describes when a heat source heats particles nearest to the heat source- making them expand. The decrease in density of particles causes the particles to rise. Then the particles cooler, denser and further away from the heat source are displaced by the heated particles- as they have risen. These particles then get closer to the heat source, expanding, becoming more dense and rise. At the same time, the previously risen particles cool, condense and sink. This process is then repeated.

Define infrared waves

The transfiguration of heat without the utilization of particles, caused by waves. These waves can travel through vacuums- regions with no particles.

Define the limit of proportionality

The maximum amount of force that can be applied to an elastic object, before it becomes inelastically deformed.

What is elastic deformation?

When an elastic object is deformed, and the limit of proportionality is not exceeded, therefore when the force is removed, the object can return to its original shape.

What is inelastic deformation

When an elastic object has been deformed beyond the limit of proportionality and cannot return to its original shape.

Define the conservation of energy

Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed.

Define thermal Energy

Energy gained by an object when it increases in tempreture.

Define nuclear Energy

Energy gained by an object when a chemical reaction is about to take place.

Define kinetic Energy

Energy gained by an object when it is in motion, increases when the objects gains speed and decreases when the objects slows down.

Define gravitational Potential Energy

Energy gained by an object when it has potential of being overcome by gravity

What is chemical energy?

Energy gained by an object when it is stationary- not moving. As well as after a chemical reaction has occured.

What is elastic potential energy

Energy gained by an object when it is elastically deformed

State the symbol equation for work done

W=F x D

What is the symbol equation to kinetic energy

Ek = 0.5 x m x v²

State the word equation to Gravitational Potential Energy

Gravitational potential energy= mass x gravitational field strength x height

What is the gravitational field strength of an object

The strength of an objects gravitational field- being the region around an object where when an objects enters it experiences a force called weight; Earth's gravitational field strength is 9.8.

State the elastic potential energy word equation

Elastic potential energy = 0.5 x spring constant x extension^2.

What is elastic deformation

When an elastic object is deformed, but its limit of proportionality is not exceeded, therefore when the force is removed, the object can return to its original shape.

What is inelastic deformation

When an elastic object it deformed, and the force applied exceeds the limit of proportionality

Define deformation

When 2 or more force are applied to an object, causing it to change shape.

State the types of Deformation

Includes compressing, stretching, or bending.

What is the process of deformation

When two or more forces is applied to an elastic object- this can be done via bending, compressing or stretching. This causes the elastic object to deform, and if an excessive amount of force (one force out of the two or more) is applied, the limit of proportionality will be exceeded and the elastic object will become inelastically deformed.

Define force application

You can only deform something when you apply two or more forces to the object.

Define an electrical field

A region around a charged object, where another charged object experiences a force.

Define electrcity

The microscopic flow of negatively charged particles called electrons through a material.

What are the different forms of radiation from radioactive decay?

Gamma rays, beta particles and alpha particles.

What occurs inside the nucleus of an atom, for radioactive decay to take place?

There must be an excessive amount of protons or neutrons which will make an imbalance in the nucleus, which will weaken the nuclear force (a force within an atom’s nucleus that holds protons and neutrons together) and the atom will loose stability. To regain stability, the atom undergoes radioactive decay at random intervals.

Explain alpha radiation

This type of radiation occurs at random, but when an atom’s nucleus has too fewer neutrons. When an atoms has too fewer neutrons than protons, it will become unstable. To regain stability, the atom emits particles consisting of 2 protons, and 2 neutrons- these particles are called alpha particles. The alpha particles emitted are in the form of an energy called radiation. This causes the relative atomic mass of the atom to decrease by 4, as it looses 2 protons (1 mass number each) and 2 neutrons ( 1 mass number each). As well as decreases the relative atomic number of an atom by 2 as 2 protons are lost.

What are the type and number of sub-atomic particles in a single alpha particle

2 protons, and 2 neutrons.

Define radioactive decay

When an atoms nucleus becomes unstable- by an imbalance of neutrons and protons in an atoms nucleus causing the nuclear force (the attractive force between neutrons and protons in a nucleus) to weaken- and emits sub-atomic particles in the form of energy (called radiation) in order to regain stability.

What are the three forms of radioactive decay?

Gamma rays, beta and alpha

Explain alpha radioactive decay

A randomly occuring process where the atoms nucleus is unstable due a neutron deficit to an excessive amount of proton ratio. It is a process where the nucleus emits an alpha particle in the form of an energy called radiation at random intervals (as the alpha particle consist of 2 protons and 2 neutrons, then alpha particle radioactive decay causes an elements relative atomic mass to decrease by 4 and the relative atomic number by 2. This makes the element become a different element)

What is the symbol for alpha particle radioactive decay?

a

Define radiation.

The emission of energy through space in the form of waves or particles.

What is a beta particle?

A highly energetic, fast moving electron emitted from an atoms nucleus during beta radioactive decay.

What are the 2 types of beta radioactive decay and their symbols?

B⁻ (beta minus) B⁺ (beta plus)

Explain beta minus radioactive decay

When an atom’s nucleus has an excessive amount of neutrons in comparison to the number of protons, it makes an imbalance of neutrons and protons- therefore the nucleus is unstable, because the nuclear force (the force of attraction between protons and neutrons that hold a nucleus together) has weakened as a result of the imbalance. At random intervals, inside an atom’s nucleus with these characteristics, a neutrons converts to a proton and emits a high energy, fast moving electron called a beta minus particle (called this due to its negative charge) and an antineutrino- a neutrally charged particle emitted alongside a beta minus particle during beta minus radioactive decay. The antineutrino serves the role of conserving energy, momentum and lepton number- being a quantum number used to represent the difference between the number of antileptons in an elementary particle within a chemical reaction.

Define a lepton number

A quantum number used to represent the difference in the number of antileptons in an elementary particle reaction.

Define an antilepton

The antiparticle counter part to leptons.

What lepton number does an antineutrino have?

-1. As it is apart of the antileptons particle family

What are the 3 types of lepton particles?

Antileptons, leptons and non-leptons.

What is the lepton number of antileptons?

-1

What is the lepton number for leptons?

+1

What is the lepton number for non-leptons?

0

What is meant by anti-matter?

The mirror image of the original particle.

What is the anti-matter equivilant of an electron?

A positively charged electron called a positron.

True or false. For every sub-atomic particle in the universe, there is an anti-particle equivilant, that has the exact same relative atomic mass, but is oppositely charged to the ordinary particle.

What are lepton numbers?

They are numerical figures that explain why specific particles interactions can occur, but others are restricted by nature.

What is the purpose of lepton numbers at a sub-atomic level?

They define how matter is created and transformed.

What lepton group is used in beta radioactive decay?

Electron lepton (Le) are used and are associated with electrons being emitted from an atoms nucleus, and electron neutrinos.

Explain what electron neutrinos are?

Sub-atomic particles with the same relative atomic mass as electrons- being 1/1840- but are neutrally charged, unlike an ordinary electrons negatively charged nature. These particles have the ability to surpass normal matter undetected- meaning being able to penertrate any kind of matter.

Define gamma rays

An extremely energetic, electromagnetic wave, high in frequency and short in length, and is emitted by an atom’s unstable nucleus following a process that occurs at random intervals to regain stability- this process is radioactive decay.

When are gamma rays emitted?

Following radioactive decay (via alpha radiation or beta radiation) involving the emitting of a beta, or alpha particle the nucleus of an atom that has regained stability experiences a vigorous increase in tempreture. The nucleus cools down in a similar way to gases- by emitting electromagnetic waves. Although, due to a nucleus having more energy in its particles, in comparison to a gas, the electromagnetic waves emitted from a gas -being infrared waves- are a lot less higher in energy than the electromagnetic waves emitted from a nucleus, being gamma rays. Therefore, following radioactive decay, gamma rays are emitted to cool the nucleus down.

What are the properties of alpha radiation?

Penetrating power= Skin/thin material eg paper

Ionising power=High

Range in air=5cm

What are the properties of beta radiation?

Penetrating power= 3mm of aluminum foil

Ionising power=Low

Range in air=~1m

What are the properties of gamma ray radiation?

Penetrating power= Lead/concrete

Ionising power=Very low

Range in air=>1km