Section 5: Solids, Liquids And Gases Flashcards
(21 cards)
Describe experiments to determine density using direct measurements of mass and volume
Using a set mass of one object, change the space its in. Use theformulamass/volume to find the density, it will go up as the volume decreases.
Know and use the relationship between pressure, force and area:
Pressure = force / area
Understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions
If you have a gas or liquid, it will be exerting an equal pressure in all directions.
Know and use the relationship for pressure difference:
pressure difference = height × density × g
Understand the significance of Brownian motion, as supporting evidence for particle theory
Brownian motion is the principle that particles move randomly about a space.
Particle theory says that as particles move about (randomly) they collide, when they collide with a surface the exert a pressure on the surface (like air keeping a balloon inflated.)
Understand that molecules in a gas have a random motion and that they exert a force
Molecules of gas move randomly about space. When the collide with a surface, they exert pressure on it.
Understand why there is an absolute zero of temperature which is –273C
It is impossible for temperature to go below -273C or 0 kelvin as any lower then this the volume will be non existent
Understand that an increase in temperature results in an increase in the average speed of gas molecules
If you increase the temperature of something, you increase the energy levels in it. The molecules of it will then have more kinetic energy
Understand that the Kelvin temperature of the gas is proportional to the average kinetic energy of its molecules
0k is where particles have no energy, as the Kelvin go up so does the energy.
Use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:
P1/T1 = P2/T2
Use the relationship between the pressure and volume of a fixed mass of gas at constant temperature:
P1 x V1 = P2 x V2
Describe the properties of magnetically hard and soft materials
A magnetically hard material retains its magneticpropertiesfor a long period of time/permanently They are hard to demagnetise.
A magnetically soft material looses its magnetic properties almost as soon as it leaves a magnetic field.
Understand the term ‘magnetic field line’
Magnetic field lines represent the shape and direction of a magnetic field.
Understand that magnetism is induced in some materials when they are placed in a magnetic field
Some materials that are not magnetic can become one when they are in a magnetic field. This is because the magnetic field encourages its electrons to align and form poles
Describe experiments to investigate the magnetic field pattern for a permanent bar magnet and that between two bar magnets
To track field lines you can use iron filings, which are magnetic materials, which will line up along the magnetic field. and you can use compasses which will show that the lines go from north to south. The following results will occur:
Describe how to use two permanent magnets to produce a uniform magnetic field pattern.
hold two opposite poles close to each other so that they attract as this makes a uniform magnetic field’
Understand that a voltage is induced in a conductor or a coil when it moves through a magnetic field or when a magnetic field changes through it and describe the factors which affect the size of the induced voltage
When a conductor experiences a changing magnetic field a voltage is induced across the conductor
Id the conductor is part of a complete circuit a current in the circuit flows
To increase the induced voltage: increase the strength of magnet; move the conductor faster; increase the number of coils/conductors.
Describe the generation of electricity by the rotation of a magnet within a coil of wire and of a coil of wire within a magnetic field and describe the factors which affect the size of the induced voltage
This is a dynamo. A magnet spun around a coil. The magnetic field lines are broken by the conductor
This motion produces electricity
Know and use the relationship between input (primary) and output (secondary) voltages and the turns ratio for a transformer:
Primary Voltage/No. Primary Turns = Secondary Voltage/No. Primary Turns
Know and use the relationship: input power = output power
VoltageP x CurrentP = VoltageS x CurrentS
Know and use the relationship between density, mass and volume:
Density = mass / volume
