IGCSE 0625 Physics Revision

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...