Physics Review

for the GHSGT

SpeedMeasure of how quickly an object gets from one place to another

Speed, distance and time

Speed and velocityv=d/tSteeper the line, greater the speed

Distance vs. Time

AccelerationRate of change in speed per timeExample

Driver of a car hitting the gas and traveling faster

35 mi/hr/sec

Driver of a car hitting the brakes-20 mi/hr/sec (negative acceleration)

a=200-0/0.8a=250 m/s2

MomentumThe more momentum an object has,

the more difficult it is to STOP!

Momentum

Velocity

Mass

Force A push or pullFree Body Diagram

Shows forces acting on an object

Balanced forces shown

6 N

6 N

Unbalanced Forces

Unbalanced forces shownOpposite directions so subtract to calculate net forceSame direction, add to calculate net force

2 N

6 N

Friction and air resistanceThe force between 2 objects in contact that opposes the motion of either objectTypes of friction

RollingSlidingAirViscous (fluids)

GravityThe attraction

Gravitational force between to objects is proportional to the product of their masses.

The farther away the objects are, the smaller the gravitational force.

Newton’s First Law An object at rest remains at rest and an object in motion maintains its velocity unless it experiences an unbalanced force.

Examples:Objects moving at a constant speed or not moving at all

A force will cause a mass to accelerate!

Gravity

Weight vs. Mass

w=mg F=ma

Remember the similarity between these two formulas. Weight is your mass times acceleration due to gravity 9.8 m/s/s on Earth

Work

W=FdUnit of measurement – Joule (J)Same unit of measurement as Energy!

Work: components of force must be parallel to displacement

Picking up suitcase Carrying the suitcase

Types of energySolarElectricalNuclearChemicalMechanical

PotentialKinetic

Conservation of mechanical energy

In the absence of friction, the total mechanical energy remains constant

Temperature scalesFahrenheitEnglish systemWater freezes - 32°Water boils - 212°Room temp - 68°

Celsius (centigrade)Metric systemWater freezes – 0°Water boils – 100°Room temp – 20°

Kelvin Celsius +

273

Converting Celsius and Fahrenheit

Thermal energyNot the same as temperature!Temperature measures the average kinetic energy of the molecules.Thermal energy is the sum of all the kinetic and potential energies of the molecules of the substance.Amount of thermal energy stored depends on 3 things:

Mass, temperature and amount of energy stored per degree

Heat Transfer

Insulator or conductor?

Materials that conduct heat easily are:

Thermal conductors

Materials that conduct heat poorly are:

Thermal insulators

Heat equation

Q = mcΔT

Heat energy

mass

Specific heat

Change in temperature

Amount of thermal energy stored depends on 3 things: Mass, temperature and amount of energy stored per degree

Parts of a transverse wave

Longitudinal (compressional) Waves

Waves

Frequency and wavelength

Frequency = cycles/ timeWavelength = length of waveA – Longest wavelengthC – greatest frequency and energy

A CB

v=fλ

Wave behavior

Constructive and destructive interference

How sound travels

Doppler EffectAs a rapidly moving object approaches you, you hear a higher pitch because of the compressed sound waves causing a higher frequency. As the object speeds away from you the sound waves stretch out and you hear a lower pitch because of the lower frequency.

Refraction, Diffraction and Reflection

Convex and Concave Lenses

Static electricity and Moving Electricity

(Current)

Ohm’s Law

Electrical circuit diagrams

Magnetism