Memorization
Equations
v = vo + at
v2 = vo2 + 2a(d-do)
d = do + vot + (1/2)at2
F = ma
Wnc = (KEfinal - KEinitial) + (GPEfinal - GPEinitial)
Units
One meter/second is approximately two miles/hour.
force - Newton, pound
One Newton is approximately one-quarter pound.
work & energy - Joule, calorie, kilocalorie
calorie - energy needed to raise 1.0 g of water by 1.0 degree Celsius
power - Watt, horsepower
One horsepower equals 750 Watts (ten light bulbs).
One human being consumes an average of approximately 100 Watts.
Basic Concepts & Definitions
Science is a way to answer measurable questions, a method of acquiring knowledge.
"Extraordinary claims require extraordinary evidence."
fact - an accurate measurement
hypothesis - a testable guess
theory - explains facts, and predicts new facts (most important!). Scientific theory is NOT an opinion and NOT a guess.
velocity - speed and direction
acceleration - how quickly velocity changes
energy - the stuff needed to do work
"Work transfers energy."
power - how quickly energy is used
The 1st Law of Thermodynamics: Energy is ALWAYS conserved. It cannot be created or destroyed.
The 2nd Law of Thermodynamics: Entropy (disorder) always increases in an isolated system. In other words, whenever energy is used, some energy will be wasted (made useless).
The four fundamental forces: gravity, electromagnetism, strong & weak (the nuclear forces)
inertia (mass) - a measure of how difficult it is to make something move; resistance to a CHANGE in motion
Newton's 1st Law of Motion: an object's motion cannot change without a force
Newton's 2nd Law of Motion: force = (mass)(acceleration)
Newton's 3rd law of Motion: Push something and it pushes back, with an equal force in the opposite direction. ALWAYS! (For every force, there is an equal and opposite force.)
Three conclusions from Special Relativity: as an object approaches the speed of light, its length decreases, its mass increases, and its time slows down.
General relativity - Einstein's theory of gravity. Mass bends the spacetime around it.
Big Bang theory in one sentence: The universe started very small, then expanded.
rotational inertia (moment of inertia) - a measure of how difficult it is to make something spin; depends on mass and location of rotational axis
impulse - causes a change in momentum
momentum - a measure of how difficult it is to make something stop
angular momentum - a measure of how difficult it is to make something stop spinning
torque - makes an object spin or stop spinning; rotational equivalent of force
Stress causes strain.
Bernoulli's Principle - the faster the speed of a fluid, the lower the pressure in the fluid
Archimedes' Principle - the buoyant force on an object is equal to the weight of the fluid it displaces
resonance - an object being shaken at its natural frequency
Objective measures of sound: frequency, intensity and harmonics
Subjective perceptions of sound: pitch, loudness and timbre
electric field - surrounds electric charges; causes electric force
magnetic field - surrounds MOVING electric charges; causes magnetic force
current - moving charges; transfers energy in a circuit
resistance - resists current; wastes energy in a circuit
voltage - average electrical potential energy; supplies the energy to a circuit
Changing magnetic fields induce voltages.
The wave model of light: Changing electric field causes changing magnetic field; changing magnetic field causes changing electric field.
The wave model of light: perpendicular sine waves, made of changing electric and magnetic fields
Quantum Mechanics - the theory that describes behavior at the atomic level; locations of objects described by probabilities
fermions - fundamental particles of matter (quarks & leptons)
bosons - particles that cause force; the exchange of bosons between fields causes force
photon - a light particle; the boson that causes electromagnetic force
bit - abbreviation of "binary digit"; a one or a zero
byte - eight bits