Main Flashcards
What are the benefits of using electrostatically charged spray paint?
Paint has same charge so repels = fine mist, no clumps. Object has opposite charge, attracts paint into corners and around the back
What are the advantages of wind power?
Renewable,no air pollution,low running costs, no fuel costs
What sort of electricity is needed to make transformers work?
AC; current must change direction so magnetic field keeps changing direction
Equation: kinetic energy, mass and speed
kinetic energy = ½ x mass x speed²
What is another name for the rate of flow of charge?
Current
Equation: energy transferred and work done
energy transferred = work done
Time
second, s
Describe the arrangement and motion of particles in a liquid
Irregular pattern;Able to move over/past other particles;Little space between particles;
Equation: pressure, force and area
pressure = force ÷ area
Resistance, R
ohm (Ω)
Factors which affect braking distance
Speed, weight of vehicle, quality of brakes and tryes, road surface
gravitational potential energy, mass, g and height
gravitational potential energy = mass x g x height
Give a use for x-rays
looking at the insides of things (medical imaging and other objects)
What does work done = energy transferred mean?
If you do 10J of work on a system you transfer 10J of energy to it.
What is the frequency range for human hearing
20 Hz - 20 000 Hz
What is the role of the moderator in a nuclear reactor?
To slow neutrons down so that they can cause new fissions
What particle do control rods absorb?
Neutrons
The gradient of a distance-time graph gives
Speed
Equation: pressure difference, height, density and g
pressure difference = height x density x g
What are the artificial sources of background radiation?
Medical sources, fallout from nuclear weapons testing and use, nuclear accidents
Mass, m
kilogram (kg)
Velocity
metre per second, m/s
If you double the volume of a sealed container of gas (at a constant temperature) what happens to the presure?
Pressure will halve
When investigating the relationship between pressure and volume what two quatities must you keep constant?
Temperature and mass of gas must be kept constant when investigating pressure and volume
Density, ρ
kilogram per metre cubed (kg/m³)
The initial linear part of a force-extension graph is linked to what law?
Hooke’s Law (Force is directly proportional to extension)
What is the law of reflection?
Angle of incidence = Angle of reflection
How can you prevent heat transfer by radiation?
Shiny surfaces are poor emitters. They also refelect the thermal radiation back.
What is the critical angle
When ligh hits the boundary at the critical angle the angle of refraction is 90°
Wavelength, λ
metre (m)
Comets orbit what? What shapes are their orbits?
Comets orbit stars (e.g. the Sun) in elliptical orbits
average speed, distance and time
speed = distance ÷ timeaverage speed = total distance ÷ total time
The area under a velocity-time graph gives
Distance travelled
Pressure
pascal, Panewton per metre², N/m²
How would you find the volume of a regular object (e.g. a cube of metal)
measure each side (with ruler) and multiply together
What happens when current flows through a resistor
When current flows through a resistor it heats up (this effect is used in kettles and toasters etc.)
When a magnet moves through a coil of wire what happens?
A magnet moving through a coil causes a current to flow
How can you increase the amount of voltage which is induced when moving a magnet into a coil?
Stronger magnet, move magnet faster
Name some electrical conductors (low resistance, allow current to easily flow)
Metal, graphite
When the angle of incidence is greater than the critical angle light is…
Totally internally reflected
Describe how thermal energy is transferred by radiation
Thermal radiation is an electromagnetic wave.
kilo
1 000
Name some vector quantities
Velocity,displacement,acceleration,force,momentum,moment,current
Why is a current induced in the secondary coil?
The secondary coil sees a changing magnetic field;electrons experience a force and move;which induces a current
Why is iron used as the core for a transformer?
Soft magnetic material; gains and loses magnetism easily.
What is the principle of conservation of energy
Energy cannot be created or destroyed; only changed from one form to another.
Magnets can attract or repel?
Other magnets
How is electricity generated in a generator?
A large coil is spun in a strong magentic field, this causes a force on the electrons and makes them flow producing a current.
Temperature, T
kelvin (K)
What happens to the resistance of a thermistor as it is heated
High temperatures reduces the resistance of a thermistor
Equation: charge, current and time
charge = current x time
What are the disadvantages of solar heating systems?
Unreliable (doesn’t work at night),may need additional boiler to produce hot water
What is Newton’s third law?
If object A exerts a force on object B, object B exerts an equal and opposite force on object A
Why do different planets have different values of g (gravitational field strength)
Planets with more mass (e.g. Jupiter) have a higher value of g
Equation: acceleration, change in velocity and time taken
acceleration = change in velocity ÷ time taken
What type of radioactive decay is most penetrating?
Gamma
gravitational potential energy, mass, g and height
gravitational potential energy = mass x g x height
What is felt when a current-carrying wire is in a magnetic field?
A force is felt when a wire carries a current in a magnetic field
Equation: work done, force and distance moved
work done = force x distance moved
weight, mass and gravitational field strength
weight = mass x gravitational field strength
Equation: primary voltage, secondary voltage, primary turns and secondary turns
primary voltage ÷ secondary voltage = primary turns ÷ secondary turns
Time, t
second (s)
Force
newton, N
Equation: force, mass and acceleration
force = mass x acceleration
What equation links momentum, mass and velocity?
Momentum = mass x velocity
What is the order of the EM spectrum
Radio, Microwave, Infra-red, Visible, Ultra-violet, X-ray & Gamma
How can you see the shape and direction of a magnetic field
Use plotting compasses
How would you find the volume of a small irregular object (e.g. a pebble)
submerge in water. The volume of water displaced = volume of pebble
Natural satellites (e.g. moons) and artificial satellites (e.g. Hubble) orbit what?
Planets
A galaxy is made up of…
Billions of stars
Equation: input current, input voltage, output current and output voltage
input current x input voltage = output current x output voltageIIVI = IOVO
How does a stretching seatbelt reduce injury
Increases collision time, lower deceleration (a=V/t), lower force (F=ma)
milli
1/1 000
Equation: charge, current and time
charge = current x time
How does a fuse work
When the current goes higher than the value of the fuse it melts. This breaks the circuit and stops current flowing
What happens to particles at absolute zero? What is the pressure? Why?
Paricles stop moving at absolute zero (no KE), pressure is zero as particles are not colliding with walls
Electrical hazards include….
Frayed cables, damaged sockets, water near sockets and metal objects in sockets
Mass
kilogram, kg
What part of the EM spectrum has the highest frequency (and energy)
Gamma has the highest frequency
What are the advantages of fossil fuels?
Reliable (not weather dependent),already established,high power output
What are the advantages of nuclear power?
Reliable (not weather dependent),already established,high power output
What are the energy transfers involved with nuclear power
nuclear ⇒ thermal ⇒ kinetic ⇒ electrical
What is the efficiency of this machine
useful output energy = 10Jtotal input energy = 100Jefficiency = 10/100= 0.1 or 10%
Density
kilogram per metre cubed, kg/m³
Area
metre squared, m²
Force, F
newton (N)
Give some useful uses of electrostatic charges
Paint spraying,Chimney precipitator (smoke cleaner),Photocopier,Ink Jet Printer
Frequency
hertz, Hz
Describe the arrangement and motion of particles in a solid
Regular pattern OR close packed;Vibration in position;Little space between particles
Volume, V
metre cubed (m³)
What are the disadvantages of nuclear power?
Produces long lasting radioactive waste which must be securely stored,mining hazardous
What part of the EM spectrum has the longest wavelength
Radio has the longest wavelength
What happens to the average speed of gas molecules as you heat a gas?
Average speed of gas molecules increases as you heat a gas
efficiency, useful energy output and total energy input
efficiency = useful energy output ÷ total energy input (also efficiency = useful energy output ÷ total energy output)
What are the general disadvantages of renewable sources of power?
Unreliable (weather dependent),large amount of land needed to replace a typical power station
Describe a transverse wave and give an example
Transverse waves travel at right angles to the oscillation which caused them. E.g. light, other EM waves, Mexican Waves
After two half-lives, how much of an original sample is left?
One quarter
What is the difference between scalar and vector quantities?
Vectors have a direction as well as a magnitude (size)
What happens to the resistance of an LDR as more light is shone on it?
Bright light reduces the resistance of an LDR
Equation: voltage, current and resistance
voltage = current x resistance
Mega
1 000 000
Wavelength
metre, m
How can magnetism be induced in a magnetic material?
Placing a magnet close to a magnetic material will induce magnetism in the magnetic material
List the 4 types of stored (potential) energies
Gravitational, Elastic, Nuclear, Chemical
Define the time period of a wave
Time period is how long it takes for a wave to pass a point
What has the following magnetic field shape?
Field around a current carrying wire
How can you find the frequency of a sound wave from an oscilloscope trace
Measure time period T (of one wave) Use f = 1/T (careful with milli seconds) e.g T = 3ms so f = 1/0.003 = 333Hz
What are the advantages of geothermal power?
Renewable,no air pollution,low running costs, no fuel costs
What type of radioactive decay is most ionising?
Alpha
Equation: pressure, force and area
pressure = force ÷ area
Equation: wave speed, frequency and wave length
wave speed = frequency x wave length
Equation: refractive index, angle of incidence, angle or refraction
n = sin i ÷ sin rrefractive index = sin (angle of incidence) ÷ sin (angle of refraction)
How are electromagnets made?
A coil of wire around an iron core
Equation: density, mass and volume
density = mass ÷ volume
Why are step up and step down transformers used in the National Grid?
Voltage stepped up (e.g 100x);Current drops by the same amount (100x lower);less power loss due to heating;Stepped down to be safe in homes.
What materials does conduction happen best in and why?
Solids; particles are close together so can pass energy quickly. Works best of all in metals due to free electrons.
How can air molecules move heavy smoke particles (Brownian motion)
lots of tiny, fast moving air molecules exert enough force on a smoke particle to change its direction
What’s wrong with -50K as a temperature?
You can’t have negative kelvin temperatures, absolute zero (0K) is the coldest temperature possible
What change of state happens during freezing?
liquid to solid
Resistance
ohm, ?
Equation: moment, force and perpendicular distance from pivot
moment = force x perpendicular distance from pivot
In what two ways can radioactive decay be detected?
By photographic film and by a Geiger-Müller (GM) Tube
What is the atomic number?
The number of protons
What experiment can be done to demonstrate charging by friction?
Rub a plastic rod with a cloth, show charge on coulombmeter or repel/attract other charged things.Rub a balloon on jumper / hair stick to wall.
Acceleration
metre per second squared, m/s², m/s/s
Describe the motion of gas particles
gas particles move in a random fast motion
Length
metre, m
What makes something an elastic material
Material regains original shape once stretching force is removed
Equation: kinetic energy, mass and speed
kinetic energy = ½ x mass x speed²
Our local galaxy is called
The Milky Way
Maximum diffraction happens when the gap size is?..
similar to the wavelength
Describe a longitudinal wave and give an example
Longitudinal waves travel parallel to the oscillation which caused them. E.g. sound
What is the difference between Alternating Current (AC) and Direct Current (DC)
DC (direct current) only flows in one direction. AC (alternating current) constantly changes direction.
Explain parallel circuits
Several routes for current to take, allows components to be switched on individually (e.g. lights at home), components get full supply voltage
How does bending you knees help prevent injury?
Increases collision time, lower deceleration (a=Δv/t), lower force (F=ma)
What are the disadvantages of hydroelectric power?
Floods a large area,disrupts people and animals
Magnetically hard materials….
Are difficult to magnetise but keep their magnetism
Waves transfer ……………………………… without transferring ……………………….
Waves transfer energy and information without transferring matter
List the 5 types of non stored energies
Light, sound, thermal, kinetic, electrical
Give a danger and use for infra red
Danger = skin burns,Use = cooking and night vision equipment
What type of radioactive decay emits a helium nucleus?
Alpha
Potential Difference, V
volt (V)
After four half-lives, how much of an original sample is left?
One sixteenth
Radioactive activity, A
becquerel (Bq)
weight, mass and gravitational field strength
weight = mass x gravitational field strength
The frequency of a sound wave is linked to its?.
pitch
Charge, Q
coulomb (C)
What is the nature of an electric current in a metal conductor?
A flow of negatively charged electrons flowing from the negative side of a battery or power supply
What happens to the current in a circuit when the resistance is decreased?
Current increases as resistance decreases
How can you show current is flowing in a circuit
A bulb or LED will light when a current flows. Or use an ammeter (in series)
Equation: refractive index, angle of incidence, angle or refraction
n = sin i ÷ sin r
wave speed, frequency and wave length
wave speed = frequency x wave length
Give a use for visible light
Seeing, optical fibres, photography
What are the energy transfers involved with fossil fuels
chemical ⇒ thermal ⇒ kinetic ⇒ electrical
Equation: energy transferred and work done
energy transferred = work done
Radioactive activity
becquerel, Bq
What are the natural sources of background radiation?
Radon gas, cosmic rays, the ground, food and drink
What happens to the pressure acting in a fluid as you go deeper?
pressure increases as you go deeper into a fluid
voltage, current and resistance
voltage = current x resistance
Why does an object reach terminal velocity?
As the speed and drag increase, eventually weight = drag so no resultant force
Give an example of an AC source and a DC source
Mains are an AC source. Batteries are DC sources
moment, force and perpendicular distance from pivot
moment = force x perpendicular distance from pivot
Why doesn’t DC work for transformers?
DC doesn’t change direction so the magnetic field is constant
refractive index and critical angle
n = 1 ÷ sin crefractive index = 1 ÷ sin (critical angle)
Frequency, f
hertz (Hz)
Potential Difference
volt, V
What isotope Carbon-14 often used for
radiometric dating; identifying how old something is based on the count rate of the carbon-14
Give a danger and use for ultra violet
Danger = blindness and damage to surface cells,Use = flourescent lamps, security markings
Acceleration, a
metre per second squared (m/s/s, m/s²)
What happens to the current in series circuit as more bulbs are added?
More bulbs in series increases the resistance and decreases the current
What is produced around a conductor when electrical current flows?
An electromagentic field is created when current flows
How would you describe a uniform field (3 marks)
Field lines are straight, parallel and equally spaced in a uniform field
What is the relationship between input and output power of a transformer?
Pprimary = PsecondaryIpVp = IsVs
What are circuit breakers
Circuit breakers break the circuit when the current goes higher than a certain value. Unlike fuses, they can be reset once tripped.
What type of radioactive decay can only be stopped by a few centimetres of lead?
Gamma
What particle was fired at gold foil during Rutherford’s experiments. What charge did it have?
Alpha particle which has a positive charge
Name some electrical insulators (high resistance, do not allow current to flow)
Plastic, wood, (pure) water
Volume
metre cubed, m³
If a car has 20 000J of kinetic energy, how much work do the brakes have to do to stop the car?
20 000J
Equation: force, mass and acceleration
force = mass x acceleration
The universe is made up of….
Billions of galaxies
How can you prevent heat transfer by convection?
Trap the fluids (e.g. trapping air in wool). This prevents both conduction and convection.
Equation: pressure difference, height, density and g
pressure difference = height x density x g
After three half-lives, how much of an original sample is left?
One eighth
How do radiators in your house heat a room (hint, not by radiation)
Radiators heat air which rises and produces a convection current. Cold air is drawn into the bottom of the radiator too.
Power
watt, W
What type of radioactive decay does not emit a particle?
Gamma
Which support provides more force? Why?
Moments about the box are equal. A closer to box, so needs bigger force to provide same moment as B.
Momentum
kilogram metre per second, kgm/s
How do you convert from C to K?What is 20 °C in K?What is -40 °C in K?
Add 273,20 °C + 273 = 293 K,-40 °C + 273 = 233 K
What materials does convection happen best in and why
Fluids (gases and liquids); particles must be free to move so can’t happen in a solid
If an object has 100J of gravitational potential energy when on a shelf and falls off, how much kinetic energy does it have just before hitting the floor? What have you assumed?
100J. But we assume there is no air resistance (100% efficient)
Why aren’t machines 100% efficient?
Typically some energy is lost to the surroundings as heat.
Pressure, p
pascal, newton per metre (Pa, N/m²)
Define frequency
Frequency is the number of waves going past a point per second
Moment
newton metre (Nm)
When the angle of incidence is less than the critical angle light is…
When the angle is less than the critical angle, light is refracted
Describe the structure of a transformer
Two coils of wire wrapped around a laminated iron core
How does convection produce wind?
Air is heated, expands, becomes less dense, rises, colder air rushes into the area of low pressure.
Describe how thermal energy is transferred by conduction
Particles knock into each other and pass on the energy
How can fires be prevented when refuelling aircraft (linked to electrostatic charge)
Attach Earthing strap (to discharge aircraft) before beginning to refuel
Velocity (initial, final), (u,v)
metre per second (m/s)
What are the disadvantages of solar cells?
Unreliable (doesn’t work at night or when cloudy),large area needed to replace a typical power station,inefficient
Give a use for radio
Communictions and broadcast
What are the energy transfers involved with solar heating systems
thermal ⇒ thermal
efficiency, useful energy output and total energy input
efficiency = useful energy output ÷ total energy input
Power, P
watt (W)
What happens to the speed of an object as it falls?What happens to its drag?
Speed increases (resultant force downwards)drag increases
Which way does light bend when it enters a material with a higher refractive index (e.g. air to glass)
Light bends towards the normal when it goes from air to glass
What are the advantages of solar heating systems?
Renewable,no air pollution,low running costs, no fuel costs
The rate of doing work is also known as?
Power
The amlitude of a sound wave is linked to its?.
volume
Length, l
metre (m)
Explain series circuits
Only one loop, simple, if one component fails no current flows
What are the disadvantages of wind power?
Unreliable (only works when windy),needs lots of land,visual pollution, a large number needed to replace a typical power station
How can you produce a uniform magnetic field (3 marks)
Place two attracting bar magnet poles (N&S) close together, hold them in place to avoid them touching
What change of state happens during condensing?
gas to liquid
Give a danger and use for gamma
Danger = cancer, mutation,Use = sterilising food and medical equipment
What are the disadvantages of geothermal power?
Only works in very specific places,deep drilling difficult and expensive
Moment
newton metre, Nm
Refraction is when a wave………………………..
…bends
What change of state happens during melting?
solid to liquid
What can happen to waves when they pass an edge or go through a gap?
Diffraction; waves spread out
Forces can do what to an object?
Change speed, shape or direction
What is the difference between analogue and digital signals
Analogue signals can have any value.Digital signals can ONLY be on or off
What are the disadvantages of fossil fuels?
Release CO₂ and air pollution, mining hazardous
When a wave is refracted what two things change
Speed and direction change during refraction
Equation: momentum, mass and velocity
momentum = mass x velocity
One Watt is equal to what?
1 watt is 1 joule per second
What are the energy transfers involved with wind power
kinetic ⇒ electric
What are the advantages of solar cells?
Renewable,no air pollution,low running costs, no fuel costs
What force is felt by the charged particle
No force felt as particle is moving parallel to field.
What is the easiest way to reduce risk of injury from microwaves, infra red, ultra violet or gamma
Avoid exposure
What change of state happens during boiling?
liquid to gas
Electric current
amp, A
Magnetically soft materials…
Are easy to magnetise but lose their magnetism quickly
Equation: work done, force and distance moved
work done = force x distance moved
Magnets can attract?
Magnetic materials (and other magnets too)
What type of radioactive decay can be stopped by a few centimetres of air?
Alpha
How can electrostatic charge be used to clean smoke in a chimney?
Smoke particles charged by wires and attracted to charged plates
What do the thumb and fingers represent when using Flemming’s Left Hand Rule?
thumb = force (direction of movement),First Finger = Field,seCond finger = Current
Factors which affect thinking distance
Speed, awareness (tired, alcohol)
What type of radioactive decay emits an electron?
Beta
centi
1/100
Temperature
kelvin, K
How can you prevent heat transfer by conduction?
Use insulators (such as air)
What are the energy transfers involved with solar cells
light ⇒ electrical
Only appliances with what sort of case need an Earth wire?
Appliances with metal cases; if the live wire comes loose someone could get a shock without an Earth wire.
Time
minute, hour, day, min, h, d
How can you produce more electricity in a generator?
Stronger magnet, spin coil faster
How can you increase the speed of a motor (or volume of a speaker)?
Stronger magnet, more current
What types of radioactive decay do not change an isotope’s mass number?
Beta and Gamma
Why is the image in a mirror virtual?
The image in a mirror can’t be projected onto a screen
How can you visualise the shape of a magnetic field (3 marks)
Place magnet under paper, sprinkle iron filings on top of paper, gently tap paper so filings line up with field lines.
Do isotopes have the same atomic number, or the same mass number?
Atomic number (number of protons)
What is the relationship between force and extension for a spring
Force is directly proportional to extention (if force doubles extension doubles)
Describe the arrangement and motion of particles in a gas
No pattern;Able to move freely/fast;Larger space between particles;
What two pieces of equipment are needed to display a sound wave?
Microphone and oscilloscope
Why is the iron core in a transformer laminated?
Prevents eddy currents;stops heating;keeps efficiency high.
How does a material gain a positive electrostatic charge?
Object loses electrons to gain a positive charge
How do gas particles exert pressure on a container
molecules collide with walls of container,exert a force,over a given area,pressure = force / area
One volt is equal to one?..
One joule per coulomb
What is double insulation
Appliances with plastic cases are double insulated; even if live wire comes loose inside, a user can’t be shocked
Equation: refractive index and critical angle
n = 1 ÷ sin c
Planets orbit what? What shape are their orbits?
Planets orbit stars (e.g. the Sun) in circular orbits
Energy, E
joule (J)
What type of radioactive decay can be stopped by a sheet of paper?
Alpha
Charge
coulomb, C
Where does an objects weight always act
Through its centre of gravity
How can electrostatic charge cause a fire at a petrol station.
Charge builds up on car while drivinga spark when person touches car+ fuel vapour = explosion
How do you convert from K to C? What is 300K in °C?What is 100K in °C?
Subtract 273,300K-273 = 27 °C,100K-273 = -173 °C
When two objects with a positive electrostatic charge are close together they?
Repel as like charges repel
Reflection is when a wave…………………………
…bounces off something
What are the advantages of hydroelectric power?
Renewable,no air pollution,low running costs, no fuel costs
More turns on the primary coil what sort of transformer?
Step down; voltage is bigger across the primary coil
What materials does radiation happen best in and why?
Transparent (see through) materials; thermal radiation can be absorbed by some materials and pass through others.
Name some scalar quantities
Speed,mass,volume,time,energy,charge,pressure,power
What has the following magnetic field shape?
Field around a flat coil(looks like an owl)
What is a magnetic field line?
A magnetic field line shows the direction of a magnetic field (N to S). Where lines are close together the field is strong.
A charged partical experience no force due to a magnetic field when?
Moving parallel to field
How can digital signals carry more information?
Multiplexing (e.g. different coloured light in fibre optics)Increase the frequency of the transmitter
How does a material gain a negative electrostatic charge?
Object gains electrons to gain a negative charge
What type of radioactive decay can only be stopped by a few millimetres of aluminium?
Beta
average speed, distance and time
speed = distance ÷ timespeed = distance⁄time
When a gas or liquid is at rest, what can you say about the pressure?
at a given depth, pressure in a fluid at rest acts equally in all directions
Energy
joule, J
Energy transferred per unit charge is known as?
Voltage
Electric current, I
amp (A)
What are the energy transfers involved with geothermal power
(nuclear) ⇒ thermal ⇒ kinetic ⇒ electric
Define wavelength
Wavelength is the distance between two peaks or two troughs
What are the dangers of ionising radiation?
Mutation and damage to cells and tissues
What is conservation of momentum?
Momentum before a collision (or explosion) is equal to the momentum after. Assuming no external forces act.
What is the mass number?
The total number of protons and neutrons
The gradient of a velocity-time graph gives
Acceleration
What has the following magnetic field shape?
Field around a solenoid (same shape as a bar magnet)
If the kelvin temperature of a gas doubles, what happens to the pressure it exerts?
Pressure doubles too
What are the energy transfers involved with water power
gravitational ⇒ kinetic ⇒ electric
When a wire is moved through a magnetic field what happens?
A wire moving through a magnet causes a current to flow
More turns on the secondary coil is what sort of transformer?
Step up; voltage is bigger across the secondary coil
Area, A
metre squared (m²)
What are the general advantages of renewable sources of power?
Renewable,no air pollution,low running costs, no fuel costs
Give a danger and use for microwaves
Danger = internal heating of body tissue,Use = cooking and satellite communications
What type of radioactive decay changes both an isotope’s mass number and its atomic number?
Alpha
What is the role of the control rods in a nuclear reactor?
To control the rate of reaction by absorbing neutrons
What is the force which opposes motion
Friction (e.g. against a road) or drag (e.g. moving through air)
Describe how thermal energy is transferred by convection
Hotter regions of fluid expand, become less dense and float on colder regions
What happens to the pressure of a gas in a sealed container when you heat it? Why?
Pressure increases when you heat a sealed container of gas,molecules move faster hitting walls harder and more often,more force exerted on same area,pressure increases
density, mass and volume
density = mass ÷ volume
What is the relationship between kelvin temperature of a gas and average kinetic energy its molecules?
Kelvin temperature is directly proportional to average kinetic energy.Doubling the temperature (in kelvin!) doubles KE
What are some advantages of digital signals?
Can carry more informationEasier to clean the signal (remove noise)
Equation: acceleration, change in velocity and time taken
acceleration = change in velocity ÷ time taken
Define amplitude
Amplitude is the maximum displacement above the equilibrium
