Science Flashcards
Weather
Condition of atmosphere @ certain time / place
Climate
Average weather over time
How are atmospheric pressure changes measured
Barometer
6 layers of atmosphere
- Troposphere: Weather
- Stratosphere : ozone
- Mesosphere: meteors burn up here
- Thermosphere: satellites/aurea borealis
- exosphere
- Ionosphere
3 Major cloud classifications
- Cirrus (curly)
- Stratus (sheets/layers)
- Cumulus (heaped, piled)
Cumulonimbus
thunderstorm cloud
Earths axis is
23.5 degree tilt
Eclipse
One astronomical body cuts light off from the other
Solar eclipse
Moon between earth and sun, so umbra (moons shadow) sweeps earth
Lunar eclipse
Earth comes directly between sun and moon, causing earths shadow (umbra) to fall on moon- ours moon in shadow
Asteroids
Large irregularly shaped chunks of rocks, metals and other materials (a band between mars and Jupiter)
Comets
Gaseous bodies
Comet head
Small brightly reflective, nucleus’s made of ice, frozen gases and other particles, when these gases approach the sun, it streams off to form the tail
Meteor
Small piece of extra terrestrial matter that is visible when it enters earths atmosphere . Meteors are large enough to reach earths surface = meteorite
Electrons
Move at speed of light
Magnetism
Generated electricity - force between certain objects
Electricity
Produced magnetic field - this magnetic field is the area around a magnet where the force is felt
Electric current
Flow of electrons from - to less - or - to +, direction is determined by polarity of voltage surface
Circuit
Pathway for moving electrons
Amperes
Magnitude or size of a current
Coulomb (c)
Electrons stored on an object (static charge) and not moving.
1 ampere = one coloumb of charge passing a point in one second
I = Q/T (
I = current in amperes, Q = change in coloumbs , T = time
Conductor
Electricity passes easily (eg silver, copper, aluminum), presence of free electrons
Insulator
Material with very few free electrons (glass wood rubber)
Semiconductors
Halfway between a good conductor and a good insulator
Resistors
Devices used to measure amount of opposition or resistance to flow of electrons, measured in Ohms
Power
Rare at which work is done. Watts is unit for power,
Watt = J/S Joules is energy work
j = N x m
Work done when point of application of Force of one newton is displaced by distance of 1 meter in direction of force
Kilowatt
Amount of electric energy used or available
Anytime there is movement, there is
Resistente
Kilowattt hour
KWh = 1,000 watts used per hour
Typically higher temp = higher
Resistance
Matter
Anything that occupies space and has mass
Mass
Quantity of matter substance possesses, a constant
Inertia
Resistance to change of position or motiob
density
Relationship of mass to a unit of volume
Energy
Ability to do work
Potential energy
Result of position of an object
Kinetic energy
Energy in motion
Force
Can change velocity of an object by making it start, stop, speed up, slow down, change direction
Friction
When something is moving, friction always acts to slow down the relative motion. Sliding friction: force generated when 2 objects are in contact and there is relative motion between them
Spring scale
Used to measure all kinds of forces - calibrated in pounds or newtons
Measurements: newtons in pound, and Oz in pound
4.45 newtons =1.0004 pound-forces
16 oz =0.454 kg = 1. Lb
When in EQ velocity
Is not changing
Viscous drag
Like friction acts opposite of velocity when solid moved through liquid
Gases also produce
Viscous drag
Weight
Force of gravity = mass x acceleration by gravity , directly proportional to accesorios caused by gravity and to mass
Weight
Directly
Newtons
Multiply mass in KG by acceleration in meters / s ^2, weight comes out in newtons
Elastic recoil
Solid Defined shape resisting changes to its shape, exerts a force to whatever is being applied to it
Bouyancy
Force acting in an upward direction in anything submerged in liquid or gad
Why does a rock sink
Weight is greater than the buoyancy of the water
Force only exists in pairs
Considered action and reaction
Equilibrium
No next forcé + velocity doesn’t change - when 2 forced eliminate each others effects - may or may not be at rest
Airplane traveling at constant speed is in equilibrium under how many forces
4- two vertical (gravity, down; lift, up-provided by flow across the wing)
, two horizontal: viscous drag (pulling back, slowing) , thrust of engines (moving forward)
6 simple machines in physics
Lever, inclined plane, wedge, wheel, axle, screw, pulley- useful bc they perform work
Work input
Effort x effort distance
Work output
Load x load distance (distance load travels)
Work = F x d
Measured in N or pounds , force required to move one kilogram one meter in one second
Mechanical advantage
MA = F L / F E (force load / force effort)
Efficiency
Work out / work in
vectors
Any physical quantity that requires both a direction and amount of force or magnitude , shown geographically as an arrow
Lever
Rigid bar supported at some point by a fulcrum or pivot and has load at some orher point on the bar
Lever force
Applying force to one end caused it to pivot about the fulcrum, causing magnification of force applied to load @ another point along the bar
Inclined plane
Ideal mechanical advantage = length \ by its height
A plane (flat) surface set at an angle to another surface - results in less effort to achieve same results by applying req force over a longer distance
Wedge
Can be type of inclined plane, aka a double inclined plane moved to exert a force along the length of its sides
Wheel and axle
Wheel attached to rigid bar or axle in center - force applied to wheel caused axle to rotate- magnified output force
Screw
Inclined plane wrapped around a cylinder - rotating screw, applying torque - force is applied perpendicular to the groove, translating to a rotational force into a linear one
Pulley
Wheel w\ a groove along edge where rope/cable can be placed. Uses principle of applying force req. to move the load , ex: pulling rope = 1/2 weight of block, since it exerts 2 upward forced, but have to exert force 2x the distance
Load
Weight of object lifted
Load distance
Distance object is lifted
Effort
Force exerted on rope (in this case for a pulley)
More pulleys
By using more rope for more pulleys, every time you add, increases friction
Effort distance (for pulley)
= load distance x number of supporting strands
Hydraulic jack
Volume of cylinder = v = pi x r^2 h
Area of pistons circular face =
Pi x r^2 h
Hydraulic jack mechanical advantage
2 cylinder Q - ratio of output area (area of circular face of piston being acted upon) to the input area (area of the circular face of the piston doing the acting)
Hydraulic jack mechanical advantage between two pistons
A2/A1 = D1/D2
A1 = area of smaller cylinder
A2 = area of bigger cylinder
D1 = vertical distance moved by smaller cylinder
Cylinder question height of input
The greater the height of the input cylinder compared to output cylinder, the greater the mechanical advantage
Vise
High friction device
Power
Rate at which work is done. Done per unit time
All machines noted power output =
Power input
Chemical reactions = 4 types
- Composition: direct combination ~ 2+ elements or compounds combine to form a more complex substance
- Decomposition: reverse of composition, complex compound breaks down to simpler compounds of basic elements
- Replacement : one substance in a compound is freed and another takes its place
- Double replacement: ions in a solution combine to form a new product that then leaves the solution
Iodine
Will kill most organisms
International SU or SI
Kilometer = 1,000 m = length
Ampere = unit of electric current
Ohm = electrical resustency
Henry = unit of electrical inductance
Atom = same # of protons and electrons
