Motion The base SI units for length, time, and mass are meters, seconds, and kilograms Movement in relation to a frame of reference is called relative.

MotionThe base SI units for length, time, and mass are

meters, seconds, and kilogramsMovement in relation to a frame of reference is

called relative velocityVectors (like velocity) have both magnitude and

direction; scalars (like speed) only have magnitude

The slope of a Distance versus Time graph tells us the average speed

Velocity is calculated by dividing displacement by time

MotionAcceleration is the rate at which velocity

changesObjects that are accelerating have parabolic

Distance versus Time graphsAdding vectors together results in another

vectorChanging direction or speed will be the result

of acceleration

ForcesMass is a measurement of inertiaStatic friction is the friction when an object

hasn’t started to move yetIf the net force is zero, an object’s velocity

will not changeF = map = mv

ForcesMomentum is conserved if there are no net forces

acting on a systemImpulse is the change in momentum, and is the

product of force and timeThe electromagnetic force is the only one that

can both attract and repelThe strong nuclear force holds together protons

and neutronsThe gravitational force is the weakest of the

fundamental forces, but is the most easily observed when dealing with large objects

ForcesNewton’s Law of Universal Gravitation states

that all mass is attracted to all other massAction-reaction forces do not cancel out

because they act on different objectsForces can be acting on objects that are

either moving or not movingForces do work when they are applied in the

direction of motion

Work & EnergyPower is the rate of doing workMachines output less work than is put into

them because friction makes their efficiency less than 100%

Actual Mechanical Advantage < Ideal Mechanical Advantage

Machines change the size of force, the direction of force, and/or the distance of force

Work & EnergyWork transfers energyMechanical energy is potential + kineticEnergy is conservedFriction turns kinetic energy into thermal

energyE = mc2

Fossil fuels (coal, oil, natural gas) represent the majority of energy resources in use

Energy gets changed from one form to another

WavesWaves transfer energyTransverse waves are perpendicular & longitudinal

waves are parallel to propagation; surface waves are both

v = fλDiffraction is when a wave bends around an obstacle;

the longer the wavelength, the more it bendsWave amplitude determines energyThe Doppler Effect explains why there is an apparent

change in frequency when there is relative motion between a wave source and an observer

WavesRefraction involves the change in direction of

a wave because of a change in speedElectromagnetic waves can travel through

empty space (a vacuum)Mechanical waves require a medium in which

to travelWaves can interfere, matter cannot

LightPolarized waves only oscillate in one

directionRadio waves have low frequency and long

wavelength, low energy and penetrate lessGamma rays have high frequency and short

wavelength, more energy and penetrate moreThe Photoelectric Effect is when electrons

are emitted from a metal when high frequency light hits it

LightMirages are caused by total internal

reflectionLight is both a particle and a waveThomas Young’s double-slit experiment

showed light interfering and acting wavelikeAll electromagnetic waves have the same

speed for a given medium

ElectricityElectric charge can be positive or negativeThe SI unit for charge is CoulombsOpposite charges attract, likes repelElectric force depends directly on the size of

the charges and inversely with the square of the distance

Charge is conservedObjects can be charged by friction, induction,

and conduction

ElectricityResistance depends directly on temperature

and length, and inversely with widthV = IRCurrent is measured in AmpsIn parallel circuits, each element functions

independentlyP = IVGrounding, fuses, and circuit breakers are

common electrical safety devices

ElectricityIn series circuits, either everything works or

nothing worksMetals and other conductors have electrons

that are free to move; plastic and other insulators do not

Electric fields lines point away from positive charges and towards negative charges

The electric force is responsible for contact forces like friction and the normal force

MagnetsMagnetic fields are strongest near the polesMagnets always have both a north and a

south poleMagnetic materials are magnetized when

their magnetic domains are alignedMagnetism is ultimately caused by moving

chargesA solenoid is a stack of loops of wireFaraday’s Law relates changing magnetic

flux to induced currents

MagnetismMotors convert potential energy (chemical,

electric, etc.) into mechanical energyMoving charges are deflected perpendicular to

magnetic fields and their velocitiesTransformers change AC voltages via

inductanceThe earth’s magnetic field is caused by

convection currents in its mantleThe strength of an electromagnet is directly

proportional to the number of coils and current