Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

Physics - AQA GCSE


🇬🇧
In Inglés
Creado:


Public


0 / 5  (0 calificaciones)



» To start learning, click login

1 / 25

[Front]


What is a Vector Quantity (& Examples)
[Back]


Have Magnitude and Direction. EXAMPLES: 1) force (20 N left) 2) displacement (50 Km East) 3) velocity (11 m/s upwards) 4) acceleration (9.8 m/s² downwards) 5) momentum (250 Km m/s west) NOTE: Can be drawn (arrow length=magnitude)

Practique preguntas conocidas

Manténgase al día con sus preguntas pendientes

Completa 5 preguntas para habilitar la práctica

Exámenes

Examen: pon a prueba tus habilidades

Pon a prueba tus habilidades en el modo de examen

Aprenda nuevas preguntas

Modos dinámicos

InteligenteMezcla inteligente de todos los modos
PersonalizadoUtilice la configuración para ponderar los modos dinámicos

Modo manual [beta]

El propietario del curso no ha habilitado el modo manual
Modos específicos

Aprende con fichas
Completa la oración
Escuchar y deletrearOrtografía: escribe lo que escuchas
elección múltipleModo de elección múltiple
Expresión oralResponde con voz
Expresión oral y comprensión auditivaPractica la pronunciación
EscrituraModo de solo escritura

Physics - AQA GCSE - Marcador

0 usuarios han completado este curso. ¡sé el primero!

Ningún usuario ha jugado este curso todavía, sé el primero


Physics - AQA GCSE - Detalles

Niveles:

Preguntas:

110 preguntas
🇬🇧🇬🇧
What is a Scalar Quantity (& Examples)
Only have a magnitude or size. EXAMPLES: 1) temperature (°C) 2) mass (kg) 3) energy (J) 4) distance (m) 5) speed (m/s) 6) volume (kg/m³)
What is a Vector Quantity (& Examples)
Have Magnitude and Direction. EXAMPLES: 1) force (20 N left) 2) displacement (50 Km East) 3) velocity (11 m/s upwards) 4) acceleration (9.8 m/s² downwards) 5) momentum (250 Km m/s west) NOTE: Can be drawn (arrow length=magnitude)
What's a Resultant Force?
A single force that has the same effect as two or more forces acting together
What do Mechanical & Electromagnetic Waves Cause oscillations in?
- Mechanical waves: cause oscillations of particles in a solid, liquid or gas and must have a medium to travel through. - Electromagnetic waves: cause oscillations in electrical and magnetic fields.
PRACTICAL: Ripple Tank (6 stages)
1) Set up ripple tank with 5cm depth of water 2) Adjust height of the wooden rod so it just touches the surface of the water 3) Switch on lamp and motor & adjust until low frequency waves can be clearly observed 4) Measure length of a number of waves then divide by the number of waves to record wavelength. Or you can take a photograph of the card with the ruler and take measurements from the still picture 5) Count the number of waves passing a point in ten seconds then divide by ten to record frequency 6) Calculate speed of the waves using: wave speed = frequency × wavelength
PRACTICAL: Measuring waves in a Solid (5 stages)
1) Attach a string or cord to a vibration generator and use a 200 gram (g) hanging mass and pulley to pull the string taut. Place a wooden bridge under the string near the pulley. 2) Switch on vibration generator and adjust the wooden bridge until stationary waves can be clearly observed 3) Measure the length of as many half wavelengths (loops) as possible, divide by the number of half wavelengths (loops) that you've measured. This is half the wavelength, doubling this gives the wavelength 4) The frequency is the frequency of the power supply 5) Calculate the speed of the waves using: wave speed = frequency × wavelength
Longitudinal & Transverse Waves
Longitudinal waves: the vibrations are parallel to the direction of wave travel transverse waves: the vibrations are at right angles to the direction of wave travel
What are the 2 key features of permenant magnets?
1)it produces its own magnetic field 2)the magnetic field cannot be turned on and off - it is there all the time
What are the 2 key features of induced magnets?
1)they are only attracted by other magnets, they are not repelled 2)they lose most or all of their magnetism when they are removed from the magnetic field
What are the 2 key features of induced magnets?
1)they are only attracted by other magnets, they are not repelled 2)they lose most or all of their magnetism when they are removed from the magnetic field
How can you test for magnetism?
1)attract or repel another permanent magnet 2)attract a magnetic material (but not repel it)
What is a magnetic field?
The reigon around a magnet where a force acts on another magnet or magnetic material.
How can you detect a magnetic field?
A compass contains a small bar magnet on a pivot so that it can rotate. The compass needle points in the direction of the Earth's magnetic field, or the magnetic field of a magnet.
List the planets in orbit to the sun.(in order)
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune
What is the trend in terms of distance from the sun?
As distance from sun increases: 1)the temperature decreases e.g. Mercury is 430 °C whereas Neptune is -200 °C 2)the time taken to orbit the Sun increases e.g. Mercury orbits once every 88 Earth days, but Neptune orbits once every 165 Earth years
What are the conditions for a planet?
1)its own gravity must be strong enough to make it round or spherical in shape. 2)Its gravitational field must also be strong enough to ‘clear the neighbourhood’, pulling smaller nearby objects into its orbit.
What is a moon?
A natural satellite.
What is are asteroids?
Small objects that orbit the sunin highly elipitical orbits take millions of years to complete made of metals and rocky material.
What are comets?
Small objects made of rocky material, dust and ice. It aproaches the sun, vapourises turning into gas then produces a distinctive tail.
Describe how the sun was formed.
1)4.6bil years ago it was a nebula - cloud of dust and gas 2)Collapsed under its own gravity transferring gravitational potential to kinetic. 3)Nebula got denser rotating more rapidly 4)Collisions between particles caused kinetic transferred to internal and thermal energy 5)Core of nebula formed hot dense protostar 6)When sun became hot enough nuclear fission happened: -energy transferred by radiation -hydrogen nuclei fuse forming helium nuclei 7)Sun is at its equilibrium: gravity pulls inwards, nuclear reaction expand outwards do gravitational collapse is balanced
What are the conditions for a satelite to be in orbit with the earth?
1)7,600m/s - stay in orbit 2)11,200 m/s or more - objects leave earths orbit 3)less than 7,600m/s - objects fall back to earth
Describe how orbiting objects are excelerating?
1)Although speed is the same, velocity changes as it is vector and includes direction this means objects are accelerating. 2)Its accelerating due the resultant force of centripal force that acts towards the middle of a circle
Prove that objects in smaller orbits travel faster than objects in large orbits.
1)gravitational attraction decreases with distance so closer objects have greater force of gravity between them so they accelerate faster 2)greater acceleration means greater velocity 3)so objects in smaller orbits travel faster than objects in large orbits
Describe the 2 types of satelite orbits.
Polar orbits: -polar orbits take satelites over earths poles -200km above sea level -speed of 8,000 m/s Geostationary orbits: -takes 24 hours to orbit earth so seem in the same position when viewed from earth -36,000km above sea level -speed of 3,000 m/s
What are Contact Forces (& 4 Examples)?
Forces that act between two objects that are physically touching each other: 1) Reaction Force - object at rest on a surface 2) Tension - object stretched 3) Friction - 2 objects sliding past each other 4) Air Resistance - object moving through air
What's Newtons 3rd Law?
When a contact force acts between two objects, both objects experience the same size force, but in opposite directions
What are Non-Contact Forces (& 3 Examples)?
Forces that act between two objects that aren't physically touching each other: 1) Magnetic forces - felt by magnetic material in a magnetic field 2) Electrostatic force - felt by any charged particle in an electric field 3) Gravitational force - Felt by any mass in a gravitational field. Masses are attracted towards each other by gravitational force
Gravitational Field
All objects with mass produce a gravitational field. Greater Mass = Greater Gravitational Field
How is Gravitational Field Produced?
GRAVITATIONAL FIELD: All objects with mass produce a gravitational field. Greater Mass = Greater Gravitational Field
Gravitational Field
All objects with mass produce a gravitational field. Greater Mass = Greater Gravitational Field
What is Weight, weightlessness & where does the weight of an object act on?
1) Weight - Force acting on an object due to gravity (non-contact) 2) Weightlessness - astronauts seem to be weightless because both they and the space station are constantly falling towards the Earth (as they are still in earth's gravitational field) 3) Centre of Mass - the weight of an object acts at its centre of mass
What are Resolving Forces, how can they be shown?
- (Opposite of Resultant Forces) A single force can be resolved (broken down) into two component forces at right angles to each other - Can be shown on Vector Diagram
Compare elastic and inelastic deformation.
Elastic deformation - the shape is reversed when the force is removed Inelastic deformation - the shape stays the same when the force is removed
What is the limit of proportionality.
The limit of proportionality is when Hooke's law (force = spring constant x extension^2) is no longer true. Due to spring been overstretched.
Hooke's law practical.
1)Secure a clamp stand to the bench using a G-clamp or a large mass on the base. 2)Use bosses to attach two clamps to the clamp stand. 3)Attach the spring to the top clamp, and a ruler to the bottom clamp. 4)Adjust the ruler so that it is vertical, and with its zero level with the top of the spring. 5)Measure and record the unloaded length of the spring. 6)Hang a 100 g slotted mass carrier - weight 0.98 newtons (N) - from the spring. Measure and record the new length of the spring. 7)Add a 100 g slotted mass to the carrier. Measure and record the new length of the spring. 8)Repeat (previous step) until you have added a total of 1,000 g. 9)Plot on a graph
What is a moment.
A moment is the turning effect of a force acting around a fulcrum (pivot) clockwise or anticlockwise
Describe a balanced object in terms of moments.
A balance object is an object which has the anticlockwise moment about a pivot equivalent to the clockwise moment.
What three components does a lever consist of?
1) pivot 2) effort 3) load Arranged in different orders
How can I decrease the effort to lift a load.
Increase the lever this will increase the distance from the effort and the pivot making it easier to lift a load.
Describe the relationship between a big gear and a small gear.
If a small gear is driven by a large gear the large gear will rotate slowly with a bigger moment. if a large gear is driven by a small gear the large gear will rotate quickly with a smaller moment.
What's Upthrust?
Resultant force upwards (felt by objects submerged). If the upthrust is less than the weight of the object, it'll sink. If the upthrust is larger than the weight of the object, it'll float
What's the Relationship between Atmospheric pressure & height & How is it caused?
Atmospheric pressure decreases as altitude incereases. Because as the altitude increases: - the number of air molecules decreases - the weight of the air decreases - there is less air above a surface
What is the Atmospheric pressure at sea level & at the Cruising altitude of a passenger plane (why must aircrafts be pressurised?)
At sea level: 101,000 Pa (101 kPa) Cruising altitude of a passenger plane: 27,000 Pa (27 kPa) ∴ air crafts must be pressurised as humans cannot take in oxygen quickly enough to meet their bodies’ needs
Typical Values for Speed (m/s)
- walking 1.5 - running 3 - cycling 6 - car 13-30 - train 50 - aeroplane 250
What is terminal velocity?
The maximum speed of an object reached when the forces moving the object are balanced by its frictional forces. The objects move at steady speed in a constant direction with a resultant force of 0.
What is inertia?
The tendancy of an object to continue in its current state of motion(rest or uniform in motion)
What does it mean if the resultant force is 0?
If resultant force is 0 then a stationary object remains stationary and a moving object remains moving. The forces are balanced
What is the required practical to investigate the effect of varying force on the acceleration of an object at a constant mass?
1)Place an air track on a bench with a bench pulley at one end and two light gates above the track. Cut an interrupt card to a length (eg 10 cm) and attach it to an air track glider. 2)Connect the glider to a hanging mass by a string that is the length of the air track passing over the bench pulley. Make sure the air track is level & the card will pass through both gates before the mass strikes the floor. 3)Set the data logging software to calculate acceleration. 4)Add 5 × 20 g slotted masses (0.98 N of force) to the end of the string. 5)Release the glider, then record the weight and acceleration. 6)Repeat steps 4 and 5 two more times, and calculate a mean value for the acceleration. 7)Repeat steps 4 to 6, removing one of the slotted masses each time ,giving forces of 0.78 N, 0.59 N, 0.39 N and 0.20 N.
What 2 factors effect braking distance?
1)Poor road and weather conditions 2)Poor vehicle condition, worn brakes/tires
How can you estimate the total stopping distance of a car using its speed?
Speed=20mp thinking distance=6m braking distance=6m total=12 AS SPEED DOUBLES, THINKING DISTANCE DOUBLES, BRAKING DISTANCE TIMES 4 SO: speed=40mp thinking distance=12m braking distance=24m total=36
What are the 3 stages of falling?
1)Accelerating downwards due to gravity 2)Frictional forces such as air resistance increase 3)The object reaches terminal velocity, weight of object balanced due to frictional forces, resultant force is 0
What is Newtons first law of motion?
An object remains in the same state of motion unless a resultant force is acting on it.
What is Newtons second law of motion?
Force(N)=mass(Kg)aceleration(m/s)
Whats inertial mass?
A mesure of how difficult it is to change the velocity of an object. Found using force over acceleration
What is Newtons third law?
Whenever two objects ineract they exert equal and opposite forces.
What is stopping distance?
Stopping distance=thinking distance+braking distance
What 4 factors effect thinking distance?
1)tiredness 2)drugs 3)alchahol 4)distractions
What is the eqaution for momentum?
P = m v p = momentum m = mass v = velocity
Why no flashcards
Because its an equation, go learn it
Describe Longitudinal Waves (in terms of Vibration direction & Particle movement) & Examples
1) the vibrations are parallel to the direction of wave travel (undergo compression & rarefaction): 2) Particles move backwards and forwards between compressions as the wave is transmitted through the medium EXAMPLES: - sound waves - ultrasound waves - seismic P-waves
Describe Transverse waves (in terms of Vibration direction & Particle movement) & Examples
1) the vibrations are at right angles to the direction of wave travel 2) Energy is transferred from left to right. However, the particles move up and down as the wave is transmitted through the medium - ripples on the surface of water - vibrations in a guitar string - a Mexican wave in a sports stadium - electromagnetic waves - eg light waves, microwaves, radio waves - seismic S-waves
4 Properties of Electromagnetic waves
1-Transverse, their vibrations are changes in electrical and magnetic fields at right angles to the direction of wave travel. They all: - transfer energy as radiation from the source of the waves to an absorber - can travel through a vacuum such as in space - travel at the same speed through a vacuum or the air - travel at 300 million metres per second (m/s) through a vacuum.
Whats the relationship between wavelength size & frequency(& energy)
- waves with a very short wavelength, high frequency and high energy - waves with a very long wavelength, low frequency and low energy
7 key features of Radio waves
1) used for communication e.g. television and radio 2) transmitted easily through air 3) do not cause damage if absorbed by the human body 4) can be reflected to change their direction 5) can be produced by oscillations in electrical circuits 6) When radio waves are absorbed by a conductor, they create an alternating current the electrical current has the same frequency as the radio waves 7) Information is coded into the wave before transmission, which can then be decoded when the wave is received
4 key features of Microwaves
1) used for cooking food and for satellite communications 2) High frequency microwaves have frequencies which are easily absorbed by molecules in food 3) The internal energy of the molecules increases when they absorb microwaves, which causes heating 4) Microwaves pass easily through the atmosphere, so they can pass between stations on Earth and satellites in orbit
5 key features of Infrared
1) used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark 2) has frequencies which are absorbed by some chemical bonds 3) The internal energy of the bonds increases when they absorb infrared light, which causes heating 4) All objects emit infrared light 5) Can be detected by infrared cameras. This 'thermal imaging' is useful for detecting people in the dark
Use of Visible Light
1) used in fibre optic communications, where coded pulses of light travel through glass fibres from a source to a receiver
3 key features of Ultraviolet
1) can have hazardous effects on the human body 2) in sunlight can cause the skin to tan or burn 3) Fluorescent substances are used in energy-efficient lamps - they absorb ultraviolet light produced inside the lamp, and re-emit the energy as visible light
How are Electromagnetic waves Used in medicine?
1) Changes in atoms and their nuclei can cause electromagnetic waves to be generated or absorbed 2) Gamma rays are produced by changes in the nucleus of an atom, they're a form of nuclear radiation 3) High energy waves such as X-rays and gamma rays are transmitted through body tissues with very little absorption. This makes them ideal for internal imaging. X-rays are absorbed by dense structures like bones, which is why X-ray photos are used to help identify broken bones
5 key features of Ionising radiation
1) Ultraviolet waves, X-rays and gamma rays are types of ionising radiation 2) They can add or remove electrons from molecules, producing electrically charged ions 3) Hazardous effects of Ionisation on the body: - UV waves can cause the skin to age prematurely and increase risk of cancer - x-rays and gamma rays can cause gene mutation, which can lead to cancer 4) radiation dose - a measure of the risk of harm caused by exposing the body to ionising radiation (Sv). As radiation dose figures are generally small, they are usually given in millisieverts (mSv) 5) background radiation - around us all the time: - radioactive rocks in the Earth's crust - cosmic rays from space - man-made sources such as nuclear weapons fallout and nuclear accidents Affected by: jobs, where people live
What is specular refrection?
Reflection from a smooth, flat surface. Happens with a flat mirror. The image in a mirror is: 1)upright 2)virtual
What is a virtual image?
When the rays appear to diverge from behind the mirror, so the image appears to come from behind the mirror.
What is diffuse reflection
When a surface is tough the light is scattered. Causing a distorted image. Each individual reflection still obeys the law of reflection, but the different parts of the rough surface are at different angles.
What is refraction?
Process by which a wave changes speed and sometimes direction upon entering a denser or less dense medium
Required practical on refraction?
1)Set up a ray box, slit and lens so that a narrow ray of light is produced. 2)Place a 30 centimetre (cm) ruler near the middle of a piece of plain A3 paper. Draw a straight line parallel to its longer sides. Use a protractor to draw a second line at right angles to this line. Label this line with an ‘N’ for ‘normal’. 3)Place the longest side of a rectangular acrylic polymer block against the first line. With the normal near the middle of the block, carefully draw around the block without moving it. 4)Use the ray box to shine a ray of light at the point where the normal meets the block. This is the incident ray. 5)The angle between the normal and the incident ray is called the angle of incidence. Move the ray box or paper to change the angle of incidence. The aim is to see a clear ray reflected from the surface of the block and another clear ray leaving the opposite face of the block. 6)Using a pencil on the paper, mark the path of: the incident ray with a cross the reflected ray with a cross the ray that leaves the block with two crosses - one near the block and the other further away 7)Remove the block. Join the crosses to show the paths of the light rays. 8)Repeat steps 2 to 7 for a rectangular glass block. 9)Measure the angle of incidence, angle of refraction and angle of reflection for each block.
What is sound?
Longitudinal waves. They cause particles to vibrate parallel to the direction of wave travel. The vibrations can travel through solids, liquids or gases. The speed of sound depends on the medium through which it is travelling. When travelling through air, the speed of sound is about 330 metres per second (m/s). Sound cannot travel through a vacuum because there are no particles to carry the vibrations.
How does the human ear detect spund?
Sound waves enter the ear canal and cause the eardrum to vibrate. Three small bones transmit these vibrations to the cochlea. This produces electrical signals which pass through the auditory nerve to the brain, where they are interpreted as sound.
Describe the amplitude and frequency of sound.
Frequency - high frequency sound waves are high pitched, low frequency sound waves are low pitched amplitude - low amplitude sound waves are quiet
What is ultra sound
Waves that have a frequency higher than the upper limit for human hearing - above 20,000 Hertz (Hz).
Give 2 uses of ultrasound
1)breaking kidney stones 2)cleaning jewellery
How does ultrasound imaging work?
A picture is formed when ultrasound waves meet the boundary between two different materials: 1)some of the ultrasound waves are reflected at the boundary 2)the time taken for the waves to leave a source and return to a detector is measured 3)the depth of the boundary can be determined using the speed of sound in the material and the time taken
Compare P and S waves?
P-longitudinal-faster-through solids and liquids S-transverse-slower-solids only
What do the waves suggest about earths structure
S-waves are not detected on the opposite side of the Earth - this suggests that the mantle has solid properties, but the outer core must be liquid. P-waves are detected on the opposite side of the Earth. Refractions between layers cause two shadow zones where no P-waves are detected. The size and positions of these shadow zones indicate there is a solid inner core.
Convex lense structure, where's the Principal of Focus & Focal length & how does the image appear?
- thicker in the middle than it is at the edges. - Parallel light rays that enter the lens converge & come together at a point called the principal focus - The distance from the lens to the principal focus is called the focal length IMAGE IS: Inverted, diminished or magnified, real
Concave lense structure, where's the principal of focus & how does the image appear?
- thinner in the middle than it is at the edges - This causes parallel rays to diverge & separate but appear to come from a principle focus on the other side of the lens IMAGE IS: Upright, diminished or magnified, virtual
Real & Virtual images & How to draw a ray diagram
Virtual image - appears to come from behind the lens Real image - an image that can be projected onto a screen HOW TO DRAW A RAY DIAGRAM: 1) Draw a ray from the object to the lens that is parallel to the principal axis. Once through the lens, the ray should pass through the principal focus. 2) Draw a ray which passes from the object through the centre of the lens
Absorption, reflection and transmission of visible light
Visible light in order of increasing frequency & decreasing wavelengths: red - orange - yellow - green - blue - indigo - violet ABSORPTION OF LIGHT: - Happens at the boundary between two different materials - the energy of the wave is transferred to the particles in the surface(internal energy of the particles increase) - some wavelengths or colours of light are absorbed, others are reflected = the colour our eyes detect TRANSMISSION OF LIGHT: - When light passes through translucent/transparent objects - Eg, an orange filter transmits orange light but absorbs all the other colours
Black bodies & the Opposite
BLACK BODIES: - No object is perfect at absorbing/emitting all the radiation, objects close to this are called: black bodies (eg, stars) - A perfect black body: would absorb all radiation that falls onto it, wouldn't reflect/transmit any radiation - A good absorber is also a good emitter POOR ABSORBERS & EMITTERS: - white & shiny silvery surfaces (worst absorbers as they also reflect all visible light wavelengths) - Radiators are usually painted white as they emit IR slowly and gradually
PRACTICAL: How the amount of IR Radiation Absorbed/Radiated Depends on the Nature of the Surface (3 Stages)
1) Place a Leslie cube on a heat-resistant mat. Fill it, almost to the top, with boiling water and replace the lid. 2) Leave for one minute, so that the surfaces heat up to the temperature of the water. 3) Use the infrared detector to measure the intensity of infrared radiation emitted from each surface, or the temperature of the surface. Make sure that the detector is the same distance from each surface for each reading Notice: Matt objects will reflect the most IR, black objects will reflect the most IR
What affects Earths Temperature?
Greenhouse gases ∴ activities like deforestation can increase temp. leading to climate change
What does Earths Temperature depend on (4 Factors)?
1- the rate at which light & IR radiation is absorbed & emitted by earths surface and atmosphere 2- greenhouse gases ∴ activities like deforestation can increase temp. leading to climate change 3- When light & high frequency IR radiation is absorbed by Earth's surface, it's internal energy increases and it becomes hotter, some of this energy is transferred to the atmosphere by conduction and convection. 4- Low frequency radiation either bounces back into space or is absorbed by GHGases
What happens as the temperature of a body(object) increases
(All objects emit IR)The hotter the body(object): - the more infrared it gives out at a time - the greater the proportion of emitted radiation as visible light
What is a soleonoid?
1)A straight coil of wire which can carry an electric current to create a magnetic field. 2)The field is similiar to the field of a bar magnet and is strong and uniform. 3)The small magnetic fields caused by the current in each coil add together to make a stronger overall magnetic field.
What is an electromagnet?
A solenoid (straight coil of wire) with an iron core is called an electromagnet. he iron core increases the solenoid’s magnetic field strength.
What is the motor effect?
The effect where force is exerted on a wire carrying a current in a magnetic field
How can we increase the force of a given length of wire in a magnetic field?
1)Increase current 2)Increase magnetic field strength
When is the force greatest?
When the current is 90degrees to the direction of magnetic field