Paper 1 Flashcards
SP1a - What are the five main scalar quantities?
Speed Mass Time Distance Temperature
SP1a - What are the six main vector quantities?
* Velocity * Displacement * Acceleration * Force * Weight * Momentum
SP1a - What is a scalar quantity?
A quantity with a magnitude (size) but no direction
SP1a - What is a vector quantity?
A quantity with a magnitude (size) and direction.
SP1b - How do you work out average speed?
Speed (m/s) = Distance(m) / Time(s)
SP1b - On a distance/time graph, what does a curve represent?
The object is accelerating/deccelerating
SP1b - On a distance/time graph, what does a horizontal line tell us?
The object is stationary
SP1b - On a distance/time graph, what does the gradient represent?
The velocity
SP1b - What are the two things you can use to measure speed in an experiment?
* Stopwatch * Light gates
SP1b - What is the average speed of walking and cycling?
* Walking: 1.4m/s * Cycling: 6m/s
SP1b - What is the speed of sound?
340 m/s
SP1c - How do you calculate acceleration?
Acceleration (m/s²)=Change in velocity (m/s) ÷ Time (s)
SP1c - What is the value of acceleration due to gravity?
9.8m/s² (rounded to 10m/s²)
SP1d - What does a curve mean on a velocity time graph?
Changing acceleration
SP1d - What does a horizontal line mean on a velocity time graph?
The object is moving at a constant velocity
SP1d - What does a straight slope mean on a velocity time graph?
Constant Acceleration
SP1d - What does the area under a velocity time graph represent?
The distance covered
SP2a - If a rocket experiences 800kN of thrust upwards and its weight is 300kN, what is the resultant force?
800 is up 300 is down.800 - 300 = 500500kN upwards
SP2b - How can the amount of centripetal force needed for an object to remain in circular motion be altered?
The amount of force needed increases if you: * Increase the mass of the object * Increase the speed of the object * Decrease the radius of the circle
SP2b - What is centripetal force?
* A force that causes objects to follow a circular path. The force acts towards the centre of the circle
SP2b - What is Newton’s first law?
* A moving object will remain at a constant velocity until an external force acts on it. * A stationary object will remain stationary until an external force acts on it.
SP2b - What three things can provide centriputal force?
* Tension * Friction * Gravity
SP2c - Describe the forces acting on a skydiver as they jump out of a plane
As soon as they jump out, the only force acting on them is their weight and so they accelerate downwards Air resistance increases with speed and so as they accelerate, air resistance increases until eventually it is equal to their weight At this point the resultant force acting on the skydiver is 0 and so they stop changing velocity as they have reached terminal velocity Once the parachute is launched, the air resistance greatly increases causing a decceleration As the velocity decreases so does the air resistance until it is again equal to the weight It now reaches a new lower terminal velocity
SP2c - What formula links weight and mass?
w = m x g(Weight = mass x gravitational field strength)
SP2c - What is the difference between weight and mass?
Mass is the quantity of matter in an object and weight is the pull force the object experience depending on the gravitational field strength.Weight - NMass - Kg
SP2d - What equation uses Newton’s second law?
F = m x a(Force = mass x acceleration)
SP2d - What is inertial mass?
* The mass of an object found from the ratio of force divided by accelaration
SP2d - What is Newton’s second law of motion?
The acceleration of an object depends on: * Its mass * The Force acting on it
SP2d CP - How can you investigate the acceleration of a trolley using light gates?
* Attach masses to the end of the trolley hanging off the end of the table over the ramp and the pulley . * Set up two light gates measured distance apart. * Connect the light gates to a data logger. * Release that masses. using your data log information, divide the length of the card by the time the light gate was active for each of the light gates. * Divide the difference between these two velocities by the time between each of them to get the acceleration. * To investigate how mass affects this, repeat with different masses.
SP2d CP - When investigating how the mass of trolley affects acceleration, what’s one thing we need to keep the same to make it fair?
The angle of the wooden block
SP2e - What is Newtons third law?
* Every action has an equal and opposite reaction
SP2e - What is the difference between balanced forces and action-reaction forces?
Balanced forces all act on the same object, action-reaction forces act on different objects.
SP2e - When a person is standing, describe the action-reaction forces.
The downward force of weight from the person on the ground and the upward reaction force of the ground on the person.
SP2f - What equation connects force and momentum, and how can this be derived?
F = Δp / t(Force = change in momentum ÷ time)As F = m x aand a = Δv / twe can see thatF = (m x Δv) ÷ tSince m x v = pthen m x Δv = ΔpSo, F = Δp ÷ t
SP2f - What is the formula for momentum?
p = m x v(momentum [kg m/s] = mass x velocity)
SP2f - What is the law of the conservation of momentum, and how is this affected by the fact that momentum is a vector quantity?
* Total momentum before = total momentum after * Since momentum is vector, an object moving in the opposite direction has a negative momentum and this must be taken into account when calculating momentum.
SP2g - What can increase the braking distance of a car?
Increasing its momentum: * If it is moving faster * Higher mass Reducing friction: * Brakes are worn * Rain/ice/snow on the roads * Loose gravel
SP2g - What is stopping distance?
* The total distance it takes for a car to stop once the driver reacts to an external stimuli. * This consists of: Thinking distance & braking distance
SP2g - What is the average reaction time to visual stimuli and what can affect this?
* 0.25 seconds. * This can be longer if the driver has taken drugs/ alcohol or hasn’t had enough sleep
SP2h - How can you combine the formulae for work done and KE to have a formula for braking distance?
E = F x dKE = 1/2 x m x v²(1/2 x m x v²) ÷ F = dd = (m x v2) ÷ 2FMass x velocity² divded by 2 force = braking distance
SP2i - Explain how the safety features of a car link to the equation linking force and momentum.
* F = Δp / t * All the safety features of a car absorbe kinetic energy, increasing the time taken for the momentum to reduce. * As the time is increased, the force is reduced.
SP2i - What are the four main safety features of a car?
* Air bags * Crumple zones and side impact bars (Easily give way causing themsleves to crush) * Seat belts
SP3a - By what processes can energy be transferred?
* Heating * Forces * Electricity * Light * Sound
SP3a - What are the 9 energy stores?
* Kinetic * Thermal * Gravitational Potential * Elastic Potential * Sound * Light * Chemical * Nuclear * Electrical
SP3a - What diagram might you use to display the transfer of energy?
A sankey diagram, The width of the bars represent the amount of energy.
SP3a - What is the law of the conservation of energy?
* Energy cannot be created or destroyed, only transferred between stores. * In a closed system, the total start energy = the total end energy
SP3a - What is unit for measuring energy?
Joules (J)
SP3b - How do you calculate efficiency?
total useful energy output / Total energy inputEfficiency is on a scale of 0 to 1. To calculate it s a percentage, x100
SP3b - How do you distiguish useful and wasted energy on a sankey diagram?
The useful energy has an arrow going staright while the wasted energy arrow turns off.
SP3b - What is it called when energy transfers to its surroundings by heating?
Dissipation
SP3b - What is the most common form of wasted energy?
Thermal
SP3b - What might you do to moving parts to reduce energy loss and why?
* Use a lubricant. * Moving parts cause friction which causes energy to dissipate losing energy. * Lubrication reduces friction and thus energy loss by friction.
SP3c - What are the 3 different ways in which energy is transferred by heating?
* Convection - This is when part of the fluid that is warmer than the rest rises up and creates a convection current * Conduction - This is when vibrations are passed on between particles in a solid * Radiation - The only way in which energy can be transferred through a vaccuum. Infrared radiation can also pass through gases and some solid materials.
SP3c - How is a flask able to maintain the temperature of its contents?
* Silver coating on the outside and inside reflects radiation which would transfer thermal energy * Glass walls with vacuums between create a cavity stopping heat from entering or escaping * Plastic stopper stops heat from escaping
SP3c - Why do cavities in walls help insulate a house?
* It creates an air gap - air has a very low thermal conductivity. When air is trapped, it cannot form convection currents and so does not transfer much energy
SP3c - What factors affect the rate of which energy is transferred through a material by heating?
* The material’s: - Thicknessrate of energy transfer is reduced by increasing thickness- Thermal Conductivityrate of energy transfer is reduced by decreasing thermal conductivity- Temperature Difference across itrate of energy transfer is reduced by decreasing temperature difference
SP3d - As an object falls describe the change in energy stores in terms of GPE and KE.
* As an object looses height, it looses GPE this ‘lost’ energy transfers, mostly, into kinetic energy as it is moving. * Some other energy may transfer into sound energy
SP3d - What is the formula for change in gravitational potential energy.
ΔGPE = m x Δh x g(change in GPE is mass x change in height x gravitational field strength)
SP3d - What is the formula for Kinetic energy?
KE = ½ x m x v²(Kinetic energy = mass x velocity² divided by 2)
SP3d - What is the gravitational field strength on earth?
9.81 (Can be rounded to 10) m/s² or N/Kg
SP3e - Apart from the lack of sustainability, why is burning fossil fuels not beneficial?
It releases Carbon dioxide and other gases that are harmful for the environment as they contribute to climate change.
SP3e - What are the four main types of non-renewable energy sources?
Fossil fuels: * Natural gas * Coal * Oil * Nuclear
SP3f - What are the pros and cons of biofuel?
Pros: * Will never run out * Carbon neutral (Burning fuels releases carbon put planting plants took in carbon so its neutral) * Useful as they can power vehicles Cons: * Can take up space that could be used for food, this can increase the price of food.
SP3f - What are the pros and cons of hydroelectric energy?
Pros: * Very reliable * Will never run out * Won’t release carbon dioxide once installed Cons: * Habitats destroyed * Only useful when water sources are nearby
SP3f - What are the pros and cons of Tidal energy?
Pros: * Extremely reliable * Will never run out * Won’t release carbon dioxide once installed Cons: * Some argue that it harms wildlife
SP3f - What are the pros and cons of using solar panels and solar energy?
Pros: * Will never run out * Won’t release carbon dioxide once installed Cons: * Energy output depends on sun and so may not always be available
SP3f - What are the pros and cons of using wind turbines?
Pros: * Will never run out * Won’t release carbon dioxide once installed Cons: * Many have to be installed and they have low output * Takes up large spaces and soem say this spoils the view * Not reliable
SP3f- Describe how Bio-Fuels work
Bio-Fuels are used in the same way as fossil fuels - they are made from animal wastes or from plants
SP3f- Describe how electricity is generated using Tidal Power
Tidal power can generate electricity when turbines in a dam across a river estuary turn as the tides flow in and out
SP3f- Describe Hydroelectricity
This is generated by falling water in places where water can be trapped in high reservoirs
SP3f- Describe the use of Solar Energy
Solar cells in solar panels convert solar energy directly into electrical energy, in ‘‘solar farms’’ or on house roof-tops.
SP4a - Descirbe the following features of a transverse wave: * Frequency * Period * Wavelength * Amplitude
* The amount of waves passing in a second (measured in Hertz Hz. Determines pitch or colour) * The time it takes one wave to pass a point * The length in m from one point to the next identical point of a wave * The distance in m from a waves rest position to its trough or peak
SP4a - Describe a longitudinal wave, giving examples.
* Particles vibrate parallel to direction of travel * Areas of compression and rarefraction * Sound waves * Seismic P waves
SP4a - Describe a transverse wave, giving examples.
* Particles vibrate perpendicular to their direction of travel. * They transfer energy They all travel at the same speed in a vacuum (3x108) * All EM waves are examples of this * Water waves are transverse
SP4b - Using two buoys, how can you measure the speed of waves?
* Measure the distance the buoys are apart. * Record the amount of time it takes for a single wave to get from one to the other. * Do distance/time to get the wave speed.
SP4b - What are the two formulas for wave speed?
v = d/t(Velocity = distance ÷ time)v = f x λ(Velocity = frequncy x wavelength)
SP4b CP - How can you use a metal rod to investigate the speed of waves in solids?
* Suspend a metal rod using clamp stands * Hold a smartphone with a frequency app at one end * Hit the other end of the rod with a hammer and record the peak frequency * Meausure the length of the rod * Frequency x wavelength
SP4b CP - How can you use a wave tank to investigate the speed of waves?
* Set up a wave tank filled with water and a straight dipper with a ruler along the side * Vary the voltage provided to the straight dipper till there are at least 2 waves visible at any point * Count how many waves form in 10 seconds and divide by 10 to get your frequency * Using the ruler estimate the wavelength of a wave * Frequency x wavelength * Alternatively, record how long it takes the wave formed to travel a certain distance and to distance/time
SP4c - How does refraction occur?
* When a ray of light reaches an interface (boundary) between substances, it changes speed (because light’s speed is dependant on the density of the substance it travels in). * If it slows down it bends towards the normal and if it speeds up it bends away
SP4c - Using water waves as a model, explain why refraction occurs.
* Waves of water travel faster is deeper water than shallow water * They also are longitudinal so can be represented with lots of parallel lines rather than one line * When the wave of water reaches a boundary between shallow and deep, the part of each line that is furthest ahead, will reach the boundary first and slow down first. * This gradual change in which parts slow down means that the wave bends towards the normal
SP4d - What are the definitions of the following: * Reflect * Refract * Transmit * Absorb
* Reflect: The waves bounce off * Refract: The wave passes into the new material but changes direction * Transmit: The wave passes through without being absorbed or reflected * Absorbed: The wave disappears as the energy it was carrying is transferred into the material
SP4d - Why is a prism able to split white light into a spectrum?
Each frequency of light changes speed at a slightly different rate meaning that at the right angles they can be split up
SP4e - Describe the process of a sound being heard by and ear. [6 marks]
* Sound waves enter the ar canal which focuses it * The eardum is a thin membrance which vibrates due to the soundwaves’ vibrations * Vibrations are passed on to tiny bones which amplify the vibrations * Vibrations are passed on to the liquid inside the cochlea * Tiny hairs inside the cochlea detect these vibrations and convert them to electrical impulses * Impulses travel along the auditory nerve to reach the brain
SP4e - Explain why as people get older, their range of hearing may decrease.
* As people get older, the hairs of the base and apex of their cochlea can get damaged. * This means that they are no longer able to convert vibrations into impulses * Thus they can’t hear these sounds
SP4e - How does the cochlea work?
* The cochlea has a membrane covered with hair cells * Each hair cell is connected to a neurone so that when it detects a vibration of its frequency it creates and electrical signal * The cochlea is a spiral with the outmost, thickest part (the base) detecting hgih frequencies (up to 20000Hz) and the low, thinnest end (the apex) detecting lower frequencies (down to 20Hz)
SP4f - How can boats use ultrasound in sonar equipment?
* To find the depth of the water beneath them. * They fire off an ultrasound wave at 1500m/s. * They time how long it takes to return. * They use d = s x t to find out the distance hte wave travelled and divide it by 2 to find the depth of the water
SP4f - How is ultrasound used in scans?
* A probe emits ultrasound waves * Gel is used to stop it from reflecting * Some waves are reflected when they meet bones, fat, tissue etc. * The probe also detects these refelected waves * It sends these as impulses to the computer * The ultrasound imaging machine detcts the frequency of the impulses turning it into an image
SP4f - What is the human range of hearing?
20Hz - 20,000 Hz
SP4f - What is ultrasound?
Sound above 20,000 Hz
SP4f - Why is an ultrasound scan more beneficial for scanning a foetus?
* Other scans such as PET and CT would release radiation * This could harm the foetus causing mutations
SP4g - How can seismic waves be used to detect earthquakes?
Seismic waves can be detected by seismometers and give information about where earthquakes are originating
SP4g - What are seismic waves?
Vibrations produces by earthquakes
