MPhysics

define speed

rate of change of distance

what is a vector quantity

has a value and direction

what is a scalar quantity

has only a value

define acceleration

the rate of change of speed

how to find distance travelled on a speed graph

area under line

define force

a push or pull that causes a change in an objects motion

is force scalar or vector

vector

name 4 everyday forces

thrust friction weight support

define mass

the measure of the amount of matter in an object measured in kg

define weight

the downward force exerted on an object due to gravity measured in N

define friction

the contact force that opposes motion

define pressure

a measure of force applied to a particular area

define gravitational potential energy

the potential energy an object has due to its height

define kinetic energy

the energy an object has due to its movement

define work

the transformation of energy

how do you know if work is done

force and movement are in the same direction

define power

the measure of work done over time or the rate at which energy is transformed

define electrical conductor

a material that allows electric charge to flow through it easily

define electrical insulator

a material that does not allow electric charge to flow easily

define current

the rate of flow of charge measured in amperes

define voltage

the amount of energy transferred per unit charge measured in volts

define resistance

a measure of how much a material opposes the flow of electric current measured in ohms

voltage rule in series

adds up to the supply

voltage rule in parallel

same across all components

current rule in series

same across all components

current rule in parallel

adds up to the supply

resistance rule in series

combines to give more resistance

resistance rule in parallel

more pathways reduce resistance

what is a mA or mW or mJ

milli(unit) 10x-3

why does heat increase resistance

particles in the wire vibrate more, making it harder for current to pass through

relate battery life to power usage

chemical potential energy in the battery is converted into electrical potential energy when the circuit is running. the faster power/energy is used, the faster the battery runs out

advantages of parallel over series

every component connected has an equal voltage

components connected on their own branch get the whole voltage (brighter)

if one branch disconnects, the others remain powered

how do voltage and current change when a new component is added in a series circuit

resistance increases so current decreases

voltage can change as it is split differently between components

how do voltage and current change when a new component is added in a parallel circuit

resistance decreases so current increases

voltage stays the same

how do current and voltage change when 2 batteries are in series

current 1x
voltage 2x

how do current and voltage change when 2 batteries are in parallel

current 2x
voltage 1x

what direction does charge flow

positive to negative

define electric field

a region in which a charged object experiences a force

unit for electric field

Vm-1 volts per metre

E=V/d

electric field, voltage, distance

define gravity field

a region in which an object with mass experiences a force

what is F=Eq for

electric force on a charge

F=Eq

force, electric field strength, charge