Studied by 2 peopleTags & Description
velocity has direction
What is the difference between speed and velocity
average speed=distance moved/time taken
what is the equation relating average speed, time taken and distance moved?
how quick velocity is changing
what is acceleration?
acceleration=change in velocity/time taken
what is the equation relating acceleration, change in velocity and time taken?
speed
on a distance-time graph what does the gradient symbolise?
it's stopped
on a distance-time graph what does it mean when there's a flat section?
there's acceleration or deceleration
on a distance-time graph what does it mean when there are curves?
acceleration
on a velocity-time graph what does the gradient symbolise?
steady speed
on a velocity-time graph what does it mean when there is a flat section?
by working out the area under the line (with limits if trying to find the distance travelled between certain time)
on a velocity-time graph how can you find distance travelled in a certain time?
gravity
what is weight caused by?
the force of attraction between all masses
what is gravity?
false
mass includes the force of gravity. true or false?
weight=mass x gravitational field strength
give the equation relating weight, gravitational field strength and mass
slows things down
what does friction do?
gravity
what is the accelerating force that acts on all falling objects?
resistance force=accelerating force
what is terminal velocity?
balanced forces means no change in velocity
what is newton's first law?
an unbalanced force means there will be acceleration
what is newton's second law?
force=mass x acceleration
give the equation relating force, acceleration and mass
that if object A exerts a force on object B, object B with exert the same but opposite force on object A
what is newton's third law? (use object A and object B)
a quantity which has size
what is a scalar quantity?
a quantity which has size and direction
what is a vector quantity?
force, velocity, displacement, acceleration, momentum
which ones of these are vector quantities?
mass -force -velocity -temperature -time -distance -displacement -acceleration -momentum
mass, temperature, time, distance
which ones of these are scalar quantities
mass -force -velocity -temperature -time -distance -displacement -acceleration -momentum
momentum=mass x velocity
give the equation relating momentum, velocity and mass
when no external forces act
when is momentum conserved?
force
what causes changes in momentum?
force acting=change in momentum/time taken for change to happen
give the equation relating force acting, change in momentum and time taken for change to happen
they increase the time for the car to stop
how do crumple zones (google it if you don't know) help decrease the impact of a crash on a passenger?
they increase the time for the passenger to stop
how to seat belts help decrease the impact of a crash on a passenger?
they slow the passenger down
how to air bags help decrease the impact of a crash on a passenger?
the turning effect of a force
what is moment?
moment=force x distance
give the equation relating moment, force and distance
where the weight of the body acts
what is the centre of gravity of an object?
by looking at the point where lines of symmetry join
how can you find the centre of gravity in simple shapes? eg. a square
that extension is proportional to force
what does hooke's law say?
when the force is great enough
when does hooke's law stop?
the material will be elastically deformed
what happens when you increase a force past the elastic limit?
brown
what is the colour of a live wire?
green and yellow
what is the colour of an earth wire?
blue
what is the colour of a neutral wire?
live wire
what is the 1st pin on a plug?
earth wire
what is the 2nd pin on a plug?
neutral wire
what is the 3rd pin on a plug?
brass
what are the pins in a plug made of?
copper
what are the cables made of in a plug?
plastic
what is the case, cable grip and cable insulation made of?
0
what is the voltage of a neutral wire?
when the appliance has metal casing and no metal parts showing
what is meant by the term double insulated?
it blows (and the circuit breaks)
what happens to a fuse when the current is too high?
takes the current to the earth
what does an earth wire do?
current decreases
what happens to current when the resistance increases?
rate of transfer of energy
what is electrical power?
watts
what is power measured in?
electrical power=current x voltage
give the equation linking electrical power, current and voltage
energy transferred=current x voltage x time
give the equation linking energy transferred, time, current and voltage
rate of flow of charge
what is current?
anything in the circuit that slows the flow down
what is resistance?
ohm
what is the unit of resistance?
it increases
what happens to current when the voltage increases
ammeter
what is this symbol?
cell
what is this symbol?
battery
what is this symbol?
power supply, DC
what is this symbol? what type of current is this?
power supply, AC
what is this symbol? what type of current is this?
earth
what is this symbol?
fuse
what is this symbol?
transformer
what is this symbol?
filament lamp
what is this symbol?
LED
what is this symbol?
loudspeaker
what is this symbol?
microphone
what is this symbol?
electric bell
what is this symbol?
motor
what is this symbol?
fixed resistor
what is this symbol?
variable resistor
what is this symbol?
diode
what is this symbol?
LDR
what is this symbol?
thermistor
what is this symbol?
AC
what type of current is in a mains supply?
DC
what type of current is in a battery supply?
alternating current (current is always changing direction)
what is AC?
direct current (current always goes in the same direction)
what is DC?
voltage=current x resistance
give the equation linking voltage, current and resistance
filament lamp
what component is this for?
wire
what component is this for?
resistors
what component is this for?
a diode
what component is this for?
false
LDR. in bright light the resistance increases. true or false?
in burglar detectors
give an example of where an LDR can be used
temperature
what is a thermistor dependent of?
true
thermistor. in hot conditions, the resistance drops. true or false?
car engine temperature sensors
where can a thermistor be used?
true
in a series circuit if one component breaks down, the whole circuit breaks down. true or false?
false
in a series circuit all of the components have different ammeter readings. true or false?
parallel
is a voltmeter placed in parallel or in series?
Q
what is the symbol of charge?
charge=current x time
give the equation linking charge, current and time
transfers energy
when charge drops through a voltage it...
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