Physics lc3

weight vs mass

Mass is a measure of how much matter there is in an object, while weight is a measure of the size of the pull of gravity on the object.

weight =

mass x gravitational field strength

vector

a quantity with a magnitude and a direction, such as displacement

scalar quantity

a quantity only with magnitude

displacement

vector quantity that refers to "how far out of place an object is"

distance

a scalar quantity that refers to the distance between two positions

velocity

the speed of something in a given direction.

speed

the speed of something without a given direction

acceleration

the change in speed or velocity of an object over a certain timea

acceleration formula

(final velocity - initial velocity)/time

motion equation

final velocity sq - initial velocity sq = 2 x acceleration x distance

force equation

force = mass x acceleration

efficiency

useful energy output / total energy input

kinetic energy equation

KE (J)=0.5 x mass (kg) x velocity sq (m/s)

gravitational potential energy equation

GPE (J)= mass (kg)x gravitation field strength (N/kg)x height(m)

speed equation

distance / time

distance time graph

the slope tells the speed

acceleration in free fall

10 m/s/s

velocity time graph

slope tells the acceleration while area is distance

length on arrows that demonstrate a force

the magnitude of the force

resultant force

the overall force on an object

balanced force

the resultant force is 0

unbalanced force

the resultant force is not 0

balanced force on stationary object

object stays stationary

balanced force on moving object

object continues constant movement

Newton’s first law

every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.

centripetal force

the force acting on an object in circular motion that pulls it towards the axis of rotation

circular motion at constant speed

a changing velocity, an acceleration

types of centripetal force

gravity, friction, tension

Newton’s seconds law

the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object

Newton’s second law equation

F=ma

acceleration

a change in velocity

inertial mass

The ratio of force over acceleration

Newton’s Third Law

if an object A exerts a force on object B, then object B must exert a force of equal magnitude and opposite direction back on object A.

action - reaction pairs

forces of equal magnitude and opposite direction that act on different object.

law of conservation of energy

energy cannot be created or destroyed

energy stores

chemical, kinetic, elastic potential, electromagnetic, nuclear, electro static, thermal

energy transfers

mechanically, electrically, heating, radiation

renewable energy sources

bio-fuels, solar, wind, tidal, hydroelectric, geothermal

why we can’t only use renewable energy

most of our systems are formed around fossil fuels, a non-renewable energy

non renewable energy sources

fossil fuels, nuclear power

how heat can be transferred

conduction, convection, radiation

thermal insulation

the reduction of heat transfer by insulating objects

thermal conductivity

the ability of a given material to conduct/transfer heat