SPH3U - Unit 3 - Energy and Society
Work - When a force is applied to an object, so it moves a certain distance
Measured in Joules or Newton metres, and is a scalar
W = F∆d cosθ
If F and d are in the same direction, θ = 0, so cosθ = 1
At 90 degrees, there is zero work
Greater than 90 degrees, there is negative work (the work is against the object’s motion)
The area of a Force/distance graph is work
Net work is a sum of all the work, considering both positive and negative work
If a force is applied for a certain distance, but the object continues to move after the force has stopped, only use the distance that applies to the force
Energy - The ability to cause a change or to do work
Mechanical Energy - The energy an object has due to its motion or position
Kinetic Energy - The energy of motion, which increases as speed increases
Potential Energy - The stored energy of an object due to its position or condition
Gravitational Potential Energy - The potential energy that increases when an object’s height increases
Elastic Potential Energy - Type of potential energy that increases when an object is stretched
Thermal Energy - Energy that increases as temperature increases due to faster moving particles
Electromagnetic Energy - Energy that travels in waves, such as light or x-rays which does not need to travel through matter
Sound energy - Energy that is carried by vibrations in matter
Electrical Energy - Energy carried by an electrical current
Chemical Energy - Energy in food and fuel, where chemical bonds are broken down to release energy
Nuclear Energy - Energy that is released when an atom is split in half or fused together
Sun - The main source of earth’s energy
Kinetic Energy - energy due to an object’s motion
Depends on speed and mass, but speed has a bigger impact
Ek = ½ mv²
Mass is in kilograms, speed is in metres per second, and energy is in Joules
Work-Energy Principle - The net amount of mechanical work done on an object equals the object’s change in kinetic energy
Wnet = ∆Ek
Gravitational Potential Energy - Energy an object has due to its place and presence of a gravitational field
Depends on strength of gravity, vertical position from a reference point, and mass
Eg = mg∆h
Height is metres, mass is kilograms, and gravity is m/s²
Energy can convert into another type of energy
The total amount of energy will not change, but the individual types of energy may increase or decrease
Law of Conservation of Energy - The total amount of energy in the universe is conserved. There is a certain total amount of energy, and this total never changes. New energy cannot be created out of nothing, and existing energy cannot disappear. The energy that exists can only be changers from one form to another.
Energy does not go away, but its usefulness can be dissipated into wasted energy
Efficiency - A measure of the amount of useful energy compared to the total energy
Efficiency = (E out)/(E in) x 100%
Renewable Energy - A substance with an unlimited supply or a supply that can be replenished as the substance is used in the energy-transforming processes
Non-Renewable Energy - A substance that cannot be replenished as it is used
Power - The rate at which energy is transferred OR the rate at which work is done
P = W/∆t = E/∆t
E/W is measured in Joules
t is measured in seconds
Power is measured in Watts
Kinetic Molecular Theory - The theory that describes the motion of molecules or atoms in a substance in terms of kinetic energy
Everything is made of particles
Particles move
Vibrate in place for solids, fills container for liquids, and gas has no fixed shape or volume
Forces of attraction are between particles
Temperature is the average kinetic energy of the particles
Celsius - Defined by the melting point of ice and boiling point of water
Kelvin - The theoretical scale based on the motion of particles, where 0 is no kinetic energy
To convert: K -273 = C
Thermal Energy - The total amount of kinetic and potential energy of the particles in an object
Heat - The transfer of heat energy OR the flow of thermal energy from one place to another
Heat can transfer by:
Conduction - A method of heat transfer within an object or between two objects in contact
Particles at a higher temperature collide with particles at a lower temperature
In the collision, energy is transferred so the slow particles speed up
This continues until equilibrium
Conduction works best for solids
Convection - The transfer of energy by the movement of higher energy particles to an area of lower energy
Heat causes expansion, which creates less dense matter
Hot matter rises, and cool matter sinks to take its place
The movement of the particles forms a convection current
Works best in liquids and gases
Radiation - The transfer of heat through infrared (electromagnetic) waves
All waves travel at the same speed, and do not need matter
The wavelength and frequency may differ
Thermal Conductor - Materials that allow heat to flow through them more easily
Thermal Insulator - Materials that do not allow heat to flow easily
Specific Heat Capacity - The amount of heat lost or gained by a kg of a substance, so its temperature changes by one degree Celsius
ex. c of water = 4200J/kg∘C
Q = mc∆T
Q is the thermal energy released/absorbed
Homeostasis - Maintenance of a temperature in a living system
Principle of Thermal Energy Exchange - When thermal energy is transferred from a warmer object to a colder object, the amount of thermal energy released by the warmer object is equal to the amount of thermal energy absorbed by the colder object
Q(gained) = -Q(lost)
When given a temperature change, plug in the given numbers, including ∆T
When given an object placed into a substance of different temperature
Use the equation Q(gained) = -Q(lost)
gained is the object that was once cooler becoming warmer
Substitute Q = mc∆T into each equation
If solving for the final temperature, ∆T = Tf - Ti
Phase - A physically distinctive form of matter
Solid - A substance with a definitive volume and shape, where the particles do not move freely
Liquid - A substance where particles are close together, but not fixed, and a definitive volume
Gas - A substance without a definitive volume or shape, containing the most kinetic energy
Types of changes
Melting - Solid → liquid
Freezing - Liquid → solid
Boiling - Liquid → gas (throughout)
Evaporation - Liquid → gas (at surface)
Condensation - Gas → liquid
Sublimation - Solid → gas
Deposition - Gas → solid
When substances lose energy, the temperature OR the state changes (not both simultaneously)
During a change of state, energy is released or absorbed, but not detected by a thermometer
Thermal energy goes in and particles gain potential energy
Heat is added, but the potential energy increases, not the kinetic energy
This is called latent heat
Latent Heat - The total thermal energy absorbed or released when a substance changes state
Q = mL
Mass is in kg
Latent heat is Joules/kg
Latent Heat of Fusion - The amount of thermal energy required to change a solid into a liquid or vice versa
Laten Heat of Vaporization - The amount of thermal energy required to change a liquid to a gas or vice versa
Specific Latent Heat - The amount of thermal energy required for 1kg to change from one state to another
Vaporization - The process by which a liquid or solid changes to gas
Boiling Point - The specific temperature at which a liquid is warmed to a high enough temperature
The greater the air pressure, the higher the boiling point
To find the total energy of something that changes states and temperature, find each one individually, and then add
Democritus - matter is made of things called particles
J.J. Thompson - Plum pudding model (discovered electron)
Rutherford - Shot alpha particles at gold foil, and some bounced back
Bohr-Rutherford Atom
Nearly all of the mass of an atom is concentrated in a very small, positively charged nucleus
The electrons travel around the nucleus
The orbits of the electrons correspond to a specific amount of energy
The nucleus consists of positive protons and neutral neutrons
Proton Number - How many protons in the nucleus, which identifies the element
Mass Number - The total mass of protons and neutrons
Atomic Mass - The average mass of isotopes (mass of the protons, neutrons, and electrons)
Isotopes - Atoms with the same number of protons, but different mass numbers
Isotope notation:
The mass number goes above, the proton number goes below, and the element symbol goes beside
Radioisotope - An isotope that is not stable and will emit ionising radiation
Number of protons = number of electrons
Radioactive Decay - The process where an unstable nucleus becomes more stable by emitting ionising radiation
Alpha Decay - An alpha particle (He-4) with a proton number of 2 is ejected
Alpha particles can not travel far
Beta Decay - A beta particle is emitted from the nucleus
An electron or positron is not found in the orbital
Electrons have a mass number of 0 and a proton number of -1
Positrons have a mass number of 0 and a proton number of +1
Particles can be a hazard if ingested
Particles travel farther than alpha
Gamma Decay - Gamma rays, which are very high energy electromagnetic waves
Travel very far
The gamma rays (γ) have a mass and proton number of 0
In gamma decay, a photon is ejected
Radiation is probability
Half-life - The amount of time for half of the radioactive material to decay, and the time for the amount of ionising radiation to decrease by one half
Not affected by external factors, so it can be reliable for carbon dating
Half-life is a recurring pattern, to that after the time of the half-life, half of the previous amount remains
Use the equation A = A0(1/2)^(t/h) to represent half-life, or graph
Law of Conservation of Energy - The total amount of mass and energy is constant
Mass can transform into energy, and energy into mass, such that the total mass-energy in an isolated system remains constant
E = mc²
Represents the amount of energy that can be created from matter
mass is kg
c is light speed (3 × 10^8)
Atomic Mass Unit - 1/12 of a Carbon-12 atom, and 1.66 × 10^-27 kg
1 proton = 1.007 u
Mass Defect - In a nuclear reaction, it is the mass before - mass after = mass defect
The mass defect represents the amount of mass converted into the energy of that particular reaction
This, times the speed of light squared, is the binding energy
Nuclear Fission - The decomposition of large, unstable nuclei into smaller, more stable nuclei
The binding energy of the nucleus is released when struck by a neutron, and other neutrons are struck loose, creating a chain reaction
Neutrons are too fast, so they must be slowed down with rods or heavy water
The heavy water also absorbs heat, turns into steam, and turns turbines to generate electricity
CANDU reactors use Uranium-235
Work - When a force is applied to an object, so it moves a certain distance
Measured in Joules or Newton metres, and is a scalar
W = F∆d cosθ
If F and d are in the same direction, θ = 0, so cosθ = 1
At 90 degrees, there is zero work
Greater than 90 degrees, there is negative work (the work is against the object’s motion)
The area of a Force/distance graph is work
Net work is a sum of all the work, considering both positive and negative work
If a force is applied for a certain distance, but the object continues to move after the force has stopped, only use the distance that applies to the force
Energy - The ability to cause a change or to do work
Mechanical Energy - The energy an object has due to its motion or position
Kinetic Energy - The energy of motion, which increases as speed increases
Potential Energy - The stored energy of an object due to its position or condition
Gravitational Potential Energy - The potential energy that increases when an object’s height increases
Elastic Potential Energy - Type of potential energy that increases when an object is stretched
Thermal Energy - Energy that increases as temperature increases due to faster moving particles
Electromagnetic Energy - Energy that travels in waves, such as light or x-rays which does not need to travel through matter
Sound energy - Energy that is carried by vibrations in matter
Electrical Energy - Energy carried by an electrical current
Chemical Energy - Energy in food and fuel, where chemical bonds are broken down to release energy
Nuclear Energy - Energy that is released when an atom is split in half or fused together
Sun - The main source of earth’s energy
Kinetic Energy - energy due to an object’s motion
Depends on speed and mass, but speed has a bigger impact
Ek = ½ mv²
Mass is in kilograms, speed is in metres per second, and energy is in Joules
Work-Energy Principle - The net amount of mechanical work done on an object equals the object’s change in kinetic energy
Wnet = ∆Ek
Gravitational Potential Energy - Energy an object has due to its place and presence of a gravitational field
Depends on strength of gravity, vertical position from a reference point, and mass
Eg = mg∆h
Height is metres, mass is kilograms, and gravity is m/s²
Energy can convert into another type of energy
The total amount of energy will not change, but the individual types of energy may increase or decrease
Law of Conservation of Energy - The total amount of energy in the universe is conserved. There is a certain total amount of energy, and this total never changes. New energy cannot be created out of nothing, and existing energy cannot disappear. The energy that exists can only be changers from one form to another.
Energy does not go away, but its usefulness can be dissipated into wasted energy
Efficiency - A measure of the amount of useful energy compared to the total energy
Efficiency = (E out)/(E in) x 100%
Renewable Energy - A substance with an unlimited supply or a supply that can be replenished as the substance is used in the energy-transforming processes
Non-Renewable Energy - A substance that cannot be replenished as it is used
Power - The rate at which energy is transferred OR the rate at which work is done
P = W/∆t = E/∆t
E/W is measured in Joules
t is measured in seconds
Power is measured in Watts
Kinetic Molecular Theory - The theory that describes the motion of molecules or atoms in a substance in terms of kinetic energy
Everything is made of particles
Particles move
Vibrate in place for solids, fills container for liquids, and gas has no fixed shape or volume
Forces of attraction are between particles
Temperature is the average kinetic energy of the particles
Celsius - Defined by the melting point of ice and boiling point of water
Kelvin - The theoretical scale based on the motion of particles, where 0 is no kinetic energy
To convert: K -273 = C
Thermal Energy - The total amount of kinetic and potential energy of the particles in an object
Heat - The transfer of heat energy OR the flow of thermal energy from one place to another
Heat can transfer by:
Conduction - A method of heat transfer within an object or between two objects in contact
Particles at a higher temperature collide with particles at a lower temperature
In the collision, energy is transferred so the slow particles speed up
This continues until equilibrium
Conduction works best for solids
Convection - The transfer of energy by the movement of higher energy particles to an area of lower energy
Heat causes expansion, which creates less dense matter
Hot matter rises, and cool matter sinks to take its place
The movement of the particles forms a convection current
Works best in liquids and gases
Radiation - The transfer of heat through infrared (electromagnetic) waves
All waves travel at the same speed, and do not need matter
The wavelength and frequency may differ
Thermal Conductor - Materials that allow heat to flow through them more easily
Thermal Insulator - Materials that do not allow heat to flow easily
Specific Heat Capacity - The amount of heat lost or gained by a kg of a substance, so its temperature changes by one degree Celsius
ex. c of water = 4200J/kg∘C
Q = mc∆T
Q is the thermal energy released/absorbed
Homeostasis - Maintenance of a temperature in a living system
Principle of Thermal Energy Exchange - When thermal energy is transferred from a warmer object to a colder object, the amount of thermal energy released by the warmer object is equal to the amount of thermal energy absorbed by the colder object
Q(gained) = -Q(lost)
When given a temperature change, plug in the given numbers, including ∆T
When given an object placed into a substance of different temperature
Use the equation Q(gained) = -Q(lost)
gained is the object that was once cooler becoming warmer
Substitute Q = mc∆T into each equation
If solving for the final temperature, ∆T = Tf - Ti
Phase - A physically distinctive form of matter
Solid - A substance with a definitive volume and shape, where the particles do not move freely
Liquid - A substance where particles are close together, but not fixed, and a definitive volume
Gas - A substance without a definitive volume or shape, containing the most kinetic energy
Types of changes
Melting - Solid → liquid
Freezing - Liquid → solid
Boiling - Liquid → gas (throughout)
Evaporation - Liquid → gas (at surface)
Condensation - Gas → liquid
Sublimation - Solid → gas
Deposition - Gas → solid
When substances lose energy, the temperature OR the state changes (not both simultaneously)
During a change of state, energy is released or absorbed, but not detected by a thermometer
Thermal energy goes in and particles gain potential energy
Heat is added, but the potential energy increases, not the kinetic energy
This is called latent heat
Latent Heat - The total thermal energy absorbed or released when a substance changes state
Q = mL
Mass is in kg
Latent heat is Joules/kg
Latent Heat of Fusion - The amount of thermal energy required to change a solid into a liquid or vice versa
Laten Heat of Vaporization - The amount of thermal energy required to change a liquid to a gas or vice versa
Specific Latent Heat - The amount of thermal energy required for 1kg to change from one state to another
Vaporization - The process by which a liquid or solid changes to gas
Boiling Point - The specific temperature at which a liquid is warmed to a high enough temperature
The greater the air pressure, the higher the boiling point
To find the total energy of something that changes states and temperature, find each one individually, and then add
Democritus - matter is made of things called particles
J.J. Thompson - Plum pudding model (discovered electron)
Rutherford - Shot alpha particles at gold foil, and some bounced back
Bohr-Rutherford Atom
Nearly all of the mass of an atom is concentrated in a very small, positively charged nucleus
The electrons travel around the nucleus
The orbits of the electrons correspond to a specific amount of energy
The nucleus consists of positive protons and neutral neutrons
Proton Number - How many protons in the nucleus, which identifies the element
Mass Number - The total mass of protons and neutrons
Atomic Mass - The average mass of isotopes (mass of the protons, neutrons, and electrons)
Isotopes - Atoms with the same number of protons, but different mass numbers
Isotope notation:
The mass number goes above, the proton number goes below, and the element symbol goes beside
Radioisotope - An isotope that is not stable and will emit ionising radiation
Number of protons = number of electrons
Radioactive Decay - The process where an unstable nucleus becomes more stable by emitting ionising radiation
Alpha Decay - An alpha particle (He-4) with a proton number of 2 is ejected
Alpha particles can not travel far
Beta Decay - A beta particle is emitted from the nucleus
An electron or positron is not found in the orbital
Electrons have a mass number of 0 and a proton number of -1
Positrons have a mass number of 0 and a proton number of +1
Particles can be a hazard if ingested
Particles travel farther than alpha
Gamma Decay - Gamma rays, which are very high energy electromagnetic waves
Travel very far
The gamma rays (γ) have a mass and proton number of 0
In gamma decay, a photon is ejected
Radiation is probability
Half-life - The amount of time for half of the radioactive material to decay, and the time for the amount of ionising radiation to decrease by one half
Not affected by external factors, so it can be reliable for carbon dating
Half-life is a recurring pattern, to that after the time of the half-life, half of the previous amount remains
Use the equation A = A0(1/2)^(t/h) to represent half-life, or graph
Law of Conservation of Energy - The total amount of mass and energy is constant
Mass can transform into energy, and energy into mass, such that the total mass-energy in an isolated system remains constant
E = mc²
Represents the amount of energy that can be created from matter
mass is kg
c is light speed (3 × 10^8)
Atomic Mass Unit - 1/12 of a Carbon-12 atom, and 1.66 × 10^-27 kg
1 proton = 1.007 u
Mass Defect - In a nuclear reaction, it is the mass before - mass after = mass defect
The mass defect represents the amount of mass converted into the energy of that particular reaction
This, times the speed of light squared, is the binding energy
Nuclear Fission - The decomposition of large, unstable nuclei into smaller, more stable nuclei
The binding energy of the nucleus is released when struck by a neutron, and other neutrons are struck loose, creating a chain reaction
Neutrons are too fast, so they must be slowed down with rods or heavy water
The heavy water also absorbs heat, turns into steam, and turns turbines to generate electricity
CANDU reactors use Uranium-235