1/53
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Physical quantity
Ang property of matter that can be measured
Measuring
When you measure something you compare it with a standard amount of the same quantity
Self luminous object
An object that gives out its own light
When can we only see a non luminous ibject
When light from some other source bounces if that object and goes into your eye
How do we know light is a form of energy
Energy if some other form is always need to produce light and light can cause a photocell to produce electric current
A beam of light may be spreading out like the beam of a torch sucha beam is called a
diverging beam
A beam of light may be getting narrower such a beam is called a
converging beam
A be of light may remain the same width such a beam is called a
Parallel beam
Light ray
A straight line showing the direction I wich light is travelling
Reflection
The bouncing of light of an object
Diffuse reflection
If the surface on wich the light shine is rough light is scattered in all directions from the surface
Mirror
If the surface on wich light shines is silvered or polished it is a mirror
Law 1 of the reflection of ligh
The incident ray , the normal at the point of incidence and the reflected Ray all lie on the same plane
Law 2 of reflection of light
The angle of incidence is equal to the angle of reflection
Virtual image
A virtual image is formed by the apparent intersection of rays
Speed
The rate of change if distance with respect to time
Constant speed
An object has constant speed if it neither speed up or slows down
When a force is removed the object may return to its original shape if this happens the object is said to be ________
Elastic
An object has an applies force too great the object may not return to its original shape the object has exceeded its _________. ________
Elastic limit
Restoring force is directly proportional to
Dosplacement
Restoring force acts in the ___ direction of displacement
Opposite
Hooked Law
When an object is bent ,stretched or compressed by a displacement the restoring force is directly proportional to the displacement provided the elastic limit is not exceeded
An object is said to be moving in simple harmonic motion if
The acceleration is directly proportional to its distance from a fixed point on its path and if the acceleration is always directed towards that point
Examples of SHM
Prongs vibrating on a tuning fork ,the tides moving in and out
Acceleration
V - U/ T
Temperature
The measure of the hitness or coldness of a body
Thermeometric propert
any physical property that changes measurably with temperature
Thermometer
An instrument based on a particular thermeometric property and is unused to measure temperature
Explain the thermometric property of a mercury thermometer
Liquids expand when heated
Explain the thermometric property of an electric thermometer
Electrical resistance increases with increasing temperature and for a semi conductor or carbon resistance decreases with increasing temperature
Emfs of a thermocouple
If two different metals are joined together to form a circuit and two junctions are kept at different temperatures a small emf is induced
What happens to the volume of gas kept at a constant pressure when heated
The volume of gas will increase
What happens to the pressure of gas at a constant pressure and then heated
It increases
Why do clinical thermometer have a small scale
They only need to read a bit above and below body temperature
What does the constriction of a clinical thermometer do
It stops the liquid flowing back into the bulb after the thermometer has been removed from the patients mouth
Heat
A form of energy that causes a rise in temperature when it is added to a hot object and a fall in temperature when it is removed from an object
Internal energy
The sum of the potential and kinetic energies of the molecules to make an object hotter we increase internal energy
Heat capacity
The amount of heat energy a substance needs to change its temperature by 1k
Specific heat capacity
The amount of energy eich will change the temperature of 1kg of the substance by 1k
What does a storage heater have
Bricks if HSHC
Latent heat
The heat energy taken in or released when a substance is changing state and not changing temperature
SLH
The amount of energy wich will change the state of 1kg of the substance
What does a heat pump do
Transfers energy from a cold to a warm body thus reducing the temperature of the cold body and rasing the temperature of the warm body
What does the pump of a heat pump have
A special liquid with a high SLH and low boling point
What does the valve of a heat pump do
It ensures the pressure on one side of the compressor is higher than the other
What does the liquid do after passing through the valve
It goes in the cold body ,the pressure is then reduced and so it expands and vaporises absorbing the necessary latent heat from surroundings making the cold body colder
What happens to the vapour after it is compressed
It changes to a liquid releasing latent heat to surroundings
Conductor
A substance that allows heat to pass through it easily
Insulator
A substance that does not allow heat to pass through it easily
U value
The amount of heat energy conducted per seonc through 1 metre squared of that substance when a temperature of 1k is maintained between its ends
What is the measure if insulating properties
The U value
The ______the u value the better the insulation
Lower
What rare the three ways heat can be transferred
Convection ,conduction and radiation