Test 7A and 7B. Monday, April 20th.

Review

Electricity can be generated in many ways. Static electricity causes object to attract one another. Is called static because it builds up on object and does not move. Current electricity flows through wires.

Measuring electrical energy: -The energy consumed by a device is measured in kilowatt/hours.

Electrical appliances use different amount of electricity. POWER refers to how much electrical energy is required to run an appliance for one second and is measured in watts. Energy usage is usually measured in kilowatts/hours and is found by multiplying the power rating of an appliance by the amount of time that the appliance is used.

Kilowatt hour: a measure of electrical energy (equal to 1000 watts being consumed for 1 hour). Power: the rate at which a device uses electrical energy (expressed in watts). Watt: a measure of the rate or energy consumption.

Photosynthesis: the process by which green plants, algae, and some bacteria use light energy, wáter and carbón dioxide to make sugars that they use for food. Cellular respiration: The process by which the energy stored in sugars is released for use by the cells of organisms.

Plants convert energy from the sun into the chemical energy in food. Animals get energy be eating plants or other animals. When plant and animals die, they become food for organism such as bacteria and fungi.

Reactant of photosyntheis: carbon dioxide and water. Products of photosynthesis, oxygen and sugar. Reactant of cellular respiration: sugars and oxygen. Products of cellular respiration: water and carbon dioxide. (Review the chemical equation of both processes; photosynthesis and cellular respiration).

Producers convert energy from the sun into chemical energy through photosynthesis. – All organisms release this energy through cellular respiration and use the energy for life processes. – energy is passed through food chains from producers to consumers.

It is possible to calculate how much energy it takes to run an appliance by multiplying the estimated number of hours it is used by its power rating. (review The Kilowatt Kids Investigate 348-349. practice exercises).

How to read a electricity meter: dials are read from left to right. Each dial represents a digit in a four digit number. The four digit number is then multiply by 10 to provide the correct number of kilowatt-hour, pointers that fall between two numbers of a dial are read as the lower of the two numbers. (practice exercise. reading a electricity meter and finding the energy consumption per month).

Most of the energy used today comes from fossil fuels, which are in limited supply. Saving energy not only saves money, bu also preserves valuable natural resources.

Energy sources and usage today are very different from those in the past. – In the last 100 years, energy use has increased dramatically.

When was the light bulb invented?? For whom? 1879 Thomas Edison. The California Electric light company begins operating the first commercial power plant to sell electricity to private customers.

When was the beginning of the automobile age? 1908. Henry Ford. Demand for petroleum.

Why do you think energy usage has increased so dramatically since 1950? The population has increased and consumers have purchased and used more energy consuming goods, such as cars, and electrical appliances.

Energy sources that can be replaced are called renewable; those that cannot are called nonrenewable. The supply of oil and other nonrenewable energy sources is running out.

Renewable resources: energy sources that can be replaced naturally, such as wood, wind, hydroelectricity, and solar energy.

Nonrenewable resources: energy sources that cannot be replaced once they are used up, such as oil, natural gas, uranium, and coal.

What is black gold? Crude oil.

What would happen without oil? What is provides? Uses of petrochemicals, Our civilization would collapse, oil makes our industrial world go around. Provides energy for factories, heat for homes, gasoline for cars, petrochemicals make plastic, paints, fibers, medicines.

What is happening with the demand and supply of oil? Demand for oil is increasing, but the supply is running out.

Other sources of energy: coal, hydroelectricity, wind, garbage, oil, sun, wood, nuclear, and natural gas.

1. Make a plan for saving energy (electricity)

TEST 11. 8A and 8B. Monday, April 20th

REVIEW

Appearances suggest that the sun moves around the Earth. The Earth appears to be motionless, and the Sun appears to move from one side of the Earth to the other. However the RETROGRADE MOTION OF MARS, AND THE SEASONAL CHANGES IN THE NIGHT SKY indicate that the Earth and other planet are revolving around the Sun.

Two models models are used to explain the motions of heavenly objects: HELIOCENTRIC AND GEOCENTRIC.

Heliocentric: The Sun is the center of the solar system and the planets revolve around the sun. Helio means Sun (Helium (an element), was first discovered in the Sun by astronomers before it was found on Earth). Held by Aristotle and Ptolemy.

Geocentric: The Earth is the center of the solar system and the Sun, the moon, and the planets revolve around the Earth. Geo means Earth. Held by Aristarchus and later Copernicus and Galileo.

The Sun rises at different locations on the horizon depending on the time of the year. It moves southward from June to December and northward from December to June.

The mean distance from the Earth to the Moon is 384,403 Km. The mean distance from Earth to the Sun is about 150 million kilometer.

How can you tell the Earth is spherical instead of flat?

We can't see all the way across it, even with a telescope. As ships disappear over the horizon, the top of the mast is the last to disappear. As you approach a point on the horizon, objects behind that point rise into view. Earth's Shadow on the Moon is curved. The Sun's angle above the horizon at noon is lower at more northern location. The Sun does not rise above the horizon at the North and South poles at certain times of year.

Day and night are caused by rotation of the Earth on its axis. Day when it is facing toward the Sun and night when it is facing ways from the sun.

Because of the Earth's tilt, sunlight strikes the Earth more directly in the Northern hemisphere during the summer than at any other time of the year. Also daylight hour are longer during the summer ,contributing to higher temperatures. When one hemisphere of the Earth is tilted toward the Sun, as the Earth rotates, that side of the Earth will be exposed to the Sun for longer period of time.

The tilt of Earth's axis causes the seasons to change. In Northern hemisphere, the Sun appears at its highest and lowest point during the summer and winter solstices, respectively.

Planet orbit the Sun in an Ellipse, NOT in a perfect circle.

Galileo Galilee, Italian astronomer. The first to effectively use the telescope. Consider himself a Copernican because he supported the idea that the planet revolve around the Sun. Was arrested for holding these ideas. (example of conflict between religion and science).

Copernicus: polish astronomer, who revived and expanded the ideas of Aristarchus. Speculated that Earth and all other planets revolve around the Sun.

The tropics include all areas on the Earth where the sun reaches a point directly overhear at lest once during the solar year. in the Temperates zones, north of the tropic of Cancer and South of the Tropic of Capricorn, the sun never reaches this zenith and is never directly overhead. The tropics of Cancer and Capricorn got their names from the fact that on the solstices, the Sun was in front of the constellations Cancer and Capricorns. But because the ellipse that describe the Earth's orbit rotates slowly with respect to the stars, the Sun is now in front of Gemini and Sagittarius at the solstices.

The Tropics, seated in the equatorial region of the world, are limited in latitude by the Tropic of Cancer in the northern hemisphere and the tropic of Capricorn in the southern hemisphere.

Solstice is an astronomical event that occurs twice each year, when the tilt of the Earth's axis is most inclined toward or ways from the Sun, causing the Sun's apparent position in the sky to reach its northernmost and southernmost extreme. (longest day and shortest day of the year (June and December) Summer and Winter solstices respectively).

Equinox: occurs twice a year, when the tilt of the Earht's axis is inclined neither ways from nor towards the Sun, The Sun being vertically above a point on the Equator. Night and day are approximately equally long. Vernal (spring) and autumnal equinoxes.

AU: Astronomical unit, is equal to 150 million kilometers.

Vocabulary: Astronomy, constellation, plane of the ecliptic, revolution, rotation. zodiac, and axis.

List: 12 constellation that make up the Zodiac, time the Earth, Mercury and Mars take to revolve once around the Sun (in days). Average distance from the Sun of Mercury, Earth and Mars on AU and kilometers

NOTAS FINALES III PARCIAL

T: Test

H: Homework

P: Presentation

SC: Science Fair

NB: Notebook

NOTAS FINALES III PARCIAL

L: Lab report
T: Test
SF: Science Fair
P: Presentation
NB: Notebook
EX: Exam