STUDY GUIDE- 1ST NINE WEEKS
INQUIRY UNIT:
Quantitative observation: observation using measurements or numbers
Ex. The bowling ball has a mass of 24 grams.(n=numbers)
Qualitative observation: observation that describes items using words
Ex. The bowling ball is purple. (l=letters)
MOTION UNIT
Formula for calculating average speed: Distance divided by time S=d/t
Formula for calculating distance: Speed times the timed= s x t
Formula for calculating time: Distance divided by speed t=d/s
Formula for calculating acceleration: Final speed minus the Initial (beginning) speed divided by time a=(Sf – SI)/ t
SPEED GRAPH: Measuring Distance and Time
Horizontal, straight line means object is at Rest
Accleration (speed vs. time) velocity graph
Horizontal, straight line means object is at constant speed or zero acceleration.
Displacement:
Curved line means object is changing direction; therefore, accelerating
`Acceleration:
- Change in direction- turning
- Speeding up
- Slowing Down
Momentum: amount of energy that a moving object has- mass in motion!
NEWTON’S 3 LAWS OF MOTION UNIT:
1st law-law of inertia (resisting a change in motion)
-An object at rest will stay at rest unless an unbalanced force acts on it.
-An object in motion will stay in motion unless an unbalanced force acts on it.
-More mass=more inertia
-friction-a force that acts to resist sliding between 2 touching surfaces
2nd law-mass and acceleration
-A net force will cause an object to change velocity and accelerate.
More mass = less acceleration (throwing a pencil vs. throwing a bowling ball)
Formula: Force = mass x acceleration
3rd law-action/reaction forces
-For every action there is an equal and opposite reaction.
-Example: If you push on a wall with 100N of force, the wall pushes back on you with 100N of force.
-Example: a person jumping on a trampoline (they are pushing down on the tramp. With their feet and this moves them up
Example: a balloon’s air is released from the bottom and this causes the balloon to move up
ELECTRICITY UNIT
Electrical power grids- way that electricity travels from a power plant throughout an area (city, neighborhood). For power to be useful in a home or business, it comes off the transmission grid and is stepped-down to the distribution grid in a power substation.
Transformer- transfers electricity from one voltage to another. Transformer (substations) can step up voltages to travel long distances and step down to a lower voltage (transformer drums) to go into homes, businesses, etc. The transformer's (drum) job is to reduce the 7,200 volts down to the 240 volts that makes up normal household electrical service.
Electric circuits-a pathway for electricity to move (Remember: a circuit is in a circle)
- series circuit is one which provides a single pathway for the current to flow. If the circuit breaks, all devices using the circuit will fail.
- parallel circuit has multiple pathways for the current to flow. If the circuit is broken the current may pass through other pathways and other devices will continue to work.
Resistance (R)-the opposition to the flow of an electric current, causing the electrical energy to be converted to thermal energy (heat) or light.
Generator: power source that uses mechanical energy (from gasoline) to make electrical energy when something is plugged into
The resistance of a short, thick piece of wire is less than the resistance of a long thin piece of wire.
AC vs DC :
Direct current (DC)-.Batteries, fuelcells and solar cells all produce direct current (DC). Current always flows in the one direction between the negative and positive terminals. (DC- Duracell battery)
Alternating current (AC) - The power that comes from a power plant. The direction of the current reverses, or alternates, 60 times per second (in the U.S.)instead of the constant flow in the direct current. (think AC-air condition-wall plug)
An alternating current is more beneficial for long distance travel because the current has to follow a shorter path and AC can be transferred from high voltage to lower voltage.
ENERGY CONSERVATION UNIT:
Renewable resources- any natural resource that provides energy and can be used over and over.
Examples: sun, wind, water (hydroelectricity), trees, and tidal
Nonrenewable resources-any natural resource from the Earth that cannot be renewed in a short period of time once it is used up
Examples: Oil, coal, natural gas (fossil fuels), and nuclear energy
Global Warming- an increase in the earth's average atmospheric temperature that causes corresponding changes in climate and may result from the greenhouse effect. Carbon Dioxide (CO2) emissions are thought to contribute
Greenhouse gases- include methane, chlorofluorocarbons and carbon dioxide (CO2). These gases act as a shield that traps heat in the earth’s atmosphere. Contributes to global warming (burning fossil fuels increases level of CO2 in air).
Ways to conserve energy: recycle, cut off lights, car pool
The Oxygen Cycle
Plants give off oxygen as a result of photosynthesis and animals/humans breathe it in and then give off CO2 through respiration.
Water cycle: evaporation, condensation, precipitation
Carbon Cycle: CO2 is absorbed by plants photosynthesis (oxygen and sugar is released) O2 and sugar is absorbed by animals/plants respiration (CO2 is released)
Carbon is returned to the soil through decomposition
Nitrogen Cycle- nitrogen gas is “fixed” by bacteria and sometimes lighteningturned into nitrogen compoundsabsorbed by plants & animalsreturned back to the atmosphere as a gas by bacteria
Weather Unit
Temperature: how hot or cold something is
*created from molecules in the air –Warm air=molecules moving quickly
Cool air=molecules moving SLLOOOWWWLY
Convection: transfer of heat by the movement of a fluid (happens within the troposphere-most of trop is heated this way)
Wind: air moving in a specific direction. Moves from areas of high pressure to areas of low pressure
Anemometer: measures wind speed
Wind vane: measures wind direction
Sea breeze: wind that blows from a body of water to the land (beach) Happens during the DAY
Land breeze: wind that blows from the land to a body of water
Happens during at NIGHT
Coriolis Effect: the way Earth’s rotation makes winds curve
•Northern Hemisphere= winds turn right
•Southern Hemisphere=winds turn left
Types of global (winds that move over long distances) winds:
•Doldrums: areas near the equator with little or no wind b/c warm air is always in place
•Horse latitudes: calm areas of falling air at 30 degrees N & S
•Trade Winds (EASTERLY WINDS): winds that blow steady from the horse latitudes TOWARD the equator. BLOW FROM THE EAST.
•Prevailing Westerlie Winds: blow north & south AWAY from the equator (blow from west to east)
•Polar Easterlies: blow cold air away from the North Pole & South Pole
•Jet Streams: bands of high speed winds that move from west to east. Located 10 km above Earth’s surface.
Jet Streams
•Air Pressure (barometric pressure): weight of a column of air pushing down on an area
•Changes in Air Pressure:
•1. High Pressure System= clear weather b/c the sinking air prevents upward movement that forms clouds (precipitation)
•Symbol is H
•2. Low Pressure System= brings rainy or stormy weather b/c the rising air encourages cloud development
•Symbol is L
•Barometer: measures air pressure
Higher altitudes (mountainous areas) have less air pressure AND the air is LESS dense.
Remember: Warm air is LESS dense (rises in the atmosphere) and has LOW atmospheric presure.
Cooler air is MORE dense (sinks in the atmosphere) and has HIGH atmospheric pressure.
Wind cools us off=moves from H to L pressure
Humidity: the amount of water vapor in the air.
–Cooler air = less water vapor
–Warmer air= more water vapor
Relative humidity : the percent of water vapor that air is currently holding.
–If the air is holding all of the water vapor it can, the relative humidity is 100%.
Dew point: the point at which air is saturated with water vapor & condensation forms.
–For condesation(clouds)to occur, the air must be cool (remember: warm air rises and cools off)
*Condensation (cloud formation) can lead to precipitation.
Precipitation: any form of water that falls to Earth from clouds (condensation-water vapor clumps together)
Ex. Sleet, freezing rain, snow, rain
•Air Mass: a large body of air that has properties that are similar to the area it forms over
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•Maritime Tropic (2 on each coast): warm, moist air
•Maritime Polar (2 on each coast): cool, moist air
•Continental Polar: cold, dry air
•Continental Tropic: hot, dry air
Front: the boundary that forms when 2 air masses having different densities, moisture or temperature touch.
Clouds, precipitation, & storms can form at frontal boundaries.
The 4 types of fronts include:
•1. Warm front: warm air moves up and over cold air. Warm air is in place. Symbolized with a red line with semicircles.
•2. Cold front: cold air moves UNDER warm air. Cold air is in place. Symbolized with a blue line with triangles.
•3. Stationary front: when a cold front and a warm front meet & neither one moves the other. Symbolized with an alternating red and blue line
•4. Occluded front: when 3 different air masses meet. Symbolized with a purple line with triangles and semicircles.
Westerly winds and jet streams move air masses across the United States (from west to east).
•Hurricanes: a large, swirling low pressure system that forms over the warm Atlantic Ocean.
•*HAS TO HAVE WARMTH & MOISTURE FOR ENERGY
•*WHEN IT HITS LAND, LOSES ENERGY
•*Easterly winds (trade winds) blow it towards land and westerly winds blow back out to sea.
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