Additional Flashcards
How can an insulated be charged by friction
Through charge of electrons
Is a material that is gaining electrons becoming positively or negatively charged
Negative
Examples of electrostatic phenomena in terms of movement of electrons
Balloon and wall
Shocks
Lightning
What is earthing
To connect something to the earth, so that any electrostatic charge can flow away
Uses of electrostatic charges
Spray paint
Insecticide sprayers
What is current in metals
Flow of electrons
What is the equation for Charge (coulomb)
Current (A) X time (s)
What type of current are cells and batteries
Direct Current
What is the equation for potential difference
Current(A) X resistance (ohm)
What is a filament lamp
Hotter means more resistance
What is a light dependant resistor
Lighter means less resistance
What are thermistors
Colder higher resistance
Advantages of heating effect of an electric current
Electric fires
Kettles
Disadvantages of heating effect of an electric current
This energy is wasted
What is displacement
The straight line from start to finish
What is velocity
How quickly an object is moving in a certain direction
On a distance time graph what is the gradient
Speed
What is the equation for speed
Distance (M) / time (S)
What is a vector quantity
Quantity that has both size and direction
In a velocity time graph what is the area
Distance
What is a reaction force
An equal and opposite reaction of something
What is the force that pushes a plane up
Lift
If the resultant force on something is 0 what happens to the movement of the object
Does not change
What is terminal velocity
A maximum velocity reached by a falling object, when weight is equal to air resistance
What is weight
Measure of the pull of gravity on an object
What is the gravitational field strength on earth
10N/Kg
In a vacuum what do all falling bodies do
Accelerate at the same rate
What is the total stopping distance
Thinking distance + braking distance
What can affect thinking distance
Drivers reaction times
What affects the braking distance
Mass of vehicle Speed of vehicle State of brakes State of road Amount of friction between tyre and road
What is linear momentum conversation
When an object collides with another object the total momentum stays the same
What do crumple zones do
When there is a crash these food in a certain way to reduce momentum
What does a seatbelt do
Reduces rate and changes momentum of the passenger
What is work
When energy is transferred from one form to another, measured in J
What is power
Rate of work, measured in W
What is an isotope
Atoms of an element with a different number of neutrons
What is the atomic number for an atom
Number of protons, appears below the symbol on the periodic table
What is the Mass number of an atom
Protons +neutrons
What are alpha particles stopped by
Paper
What are beta particles stopped by
Aluminium
What are gamma rays stopped by
Lead
What does the fission of U - 235 make
Barium - 141
Krypton - 92
What is nuclear fusion
Small nuclei make big nuclei
How many neutrons are released in nuclear fission
3
What do control rods do
Contains elements that absorb neutrons
What do moderators do
Slow down neutrons
What fusion occurs when stars are formed
Hydrogen nuclei form helium
Why can’t we create ideal conditions for fusion on earth
can’t create a strong enough gravitational field
What damage can ionising radiation cause
Tissue damage and mutations
How to prevent damage from ionising radiation
Protective cloths
Stay away from it
How long does High Level Waste (HLW) produce large amounts of ionising radiation for
50 years
How is HLW transported
Thick concrete and steel containers
How is ILW stored
Concrete and steel containers
How is LLW disposed of
Buried in special land fill cites
How long is LLW radioactive for
Tens of thousands of years
Problems of firing nuclear waste into space
Could fall back to earth, spreading radioactive material over a large are
Problems of dumping barrels on nuclear waste in the sea
Could corrode and radioactive materials could enter the food chain
Problems of storing nuclear waste underground
Site needs to be geographically stable, low risk of earthquakes
What is half life
How long it takes for half of the unstable nuclei to decay
What unit is the activity of a radioactive isotope measured
Bq
What is a GM tube
Gives a click each time radiation is detected
What is the click rate of a GM tube
Number of clicks per second or minute
Examples of background radiation
Radon gas Food Drink Rocks Cosmic rays
How do you irradiate food
Use gamma rays to kill bacteria
How do you sterilise equipment
Use gamma rays to kill bacteria
How do you diagnose cancer
Inject a gamma tracer and can be seen through a gamma camera
How do you kill cancer cells
Fire gamma rays at it