SCIENCE 7- CH15 ENERGY & IT'S FORMS

is thermal energy beneath Earth's surface. In some regions, especially near volcanoes, _________ ________ is used to generate electricity.

Geothermal Energy?

Work is the transfer of energy. When work is done on an object, energy is transferred to that object.

How are energy and work related?

An object's gravitational potential energy depends on its mass, its height, and the acceleration due to gravity. PE = mgh ; F= W=mg ; g= 9.8m/s² therefore: PE = Wh

How is gravitational potential energy determined?

2 forms. the gravitational energy and elastic potential energy.

How many forms of the potential energy?

many forms of energy can be classified into 2 general types are kinetic energy and potential energy.

How many general types of the energy?

(KE + PE) beginning = (KE + PE) ending The total mechanical energy beginning EQUAL the total mechanical energy at the end.

How to calculating the Energy Conversion? When friction is small enough to be ignored (neglect friction / no friction), NO mechanical energy is added to a system, then the system's mechanical energy DOES NOT change (the total mechanical energy remains constant).

Energy obtained from flowing water. As the water flows downhill, its gravitational PE is converted into KE used to turn turbines that are connected to electric generators.

Hydroelectric energy?

____ ____ _____ generate electricity by reacting hydrogen with oxygen, _____ _____ ____ can be used to convert energy from renewable resources.

Hydrogen fuel cells?

is the process that releases energy when less massive nuclei COMBIDE to form a more massive nucleus. The heat and light of the sun are produced by ________of hydrogen nuclei into helium nuclei.

Nuclear FUSION?

electricity.

Nuclear power plants uses nuclear fission reactions to generate ___________.

FOSSIL FUELS.

Oil, coal, and natural gas are known as ______ ______ are relatively inexpensive and are usually readily available, but their use creates pollution

are resources that can be replaced in a relatively short period of time. ____________include hydroelectric, solar, geothermal, wind, biomass and nuclear fusion.

Renewable Energy Resources? What are major renewable resources?

Sunlight that is converted into usable energy. Sunlight can also be converted directly into electrical energy. The benefits of solar energy depend on the climate.

Solar Energy?

Gravitational PE is directly related to the object's mass and its height relative to a reference level therefore gravitational PE will be doubled when you double either its mass or its height. PE = mgh 2 * PE = 2*m gh 2 * PE = mg *2*h

what happens to the gravitational PE when you doubling either the object's mass or it's height?

the potential energy PE of and object that is STRETCHED OR COMPRESSED. Something is said to be elastic if it springs back to its original shape after it is stretched or compressed.

Elastic potential energy?

the energy stored in CHEMICAL BONDS. When the wood is burned, energy for fire is the energy stored in the wood is ____________. All chemical compounds , including fuels such as coal and gasoline, are store energy.

Chemical energy?

Energy = mass * speed of light c= speed of light = 3.0 * 10⁸

E = mc²

E=mc² That energy and mass are equivalent and can be converted into each other. Also energy released as matter is destroyed, and matter can be created from energy.

Einstein's equation?

The chemical energy stored in living things. __________ ________can be converted directly into thermal energy.

Biomass Energy?

is the energy associated with ELECTRIC CHARGES. Electric charges can exert forces that do work

Electrical energy?

is a form of energy that travels through space in the form of WAVES. _____________waves can travel long distances through air and space, they are often used for communication.

Electromagnetic Energy?

For example many people around the world burn wood or peat to heat their home or cooking. Also, agricultural wastes such as corn stalks can be converted into a high-energy alcohol fuel that can be added to gasoline for cars.

Examples of Biomass Energy?

For example, ____ ____ ____ can be extracted from water using electricity from solar cells. The end product of fuel cells is WATER, so they offer a nonpolluting means for transporting energy.

Examples of Hydrogen fuel cells?

For example, sunlight passing through the windows of a house may be absorbed by thick walls that then radiate thermal energy to warm the house.

Examples of Solar Energy?

is the energy associated with the motion and position of everyday objects. It is the SUM of an object's potential energy and kinetic energy. Mechanical energy = PE + KE Speeding trains , bouncing balls, and sprinting athletes all have ____________

Mechanical energy?

SUN.

Most renewable energy resources originate either directly or indirectly from the__________.

are resources exist in limited quantities and, once used, CANNOT be replaced except over the course of millions of year. ____________are oil, natural gas, coal, and uranium.

Nonrenewable Energy Resources? What are the major nonrenewable resources?

is the process that releases energy by SPLITTING nuclei apart. A nuclear power plant uses _____ reactions to generate electric.

Nuclear FISSION?

true

The gravitational PE of an object is converted to the KE of motion as object falls. ( PE beginning = KE ending ) true or false?

Energy CANNOT be created or destroyed. Energy CAN BE CONVERTED from one form of energy to another form of energy.

The law of conservation of energy?

true

The nucleus of an atom is held by strong or weak nuclear forces, which can store an enormous amount of Potential energy. true or false?

Electrical energy.

The powerful bolts of lightning are produced by ________.

electric power, heating building or other purposes.

The sun and Earth are constantly releasing large amounts of energy. This energy could be used for generating __________, _________________.

The total PE + KE related to the motion of all the MICROSCOPIC PARTICLES in an object make up its_____________. When an object's atoms move faster, its ___________ increases and objects becomes WARMER.

Thermal energy?

Electromagnetic energy.

Visible light and X-ray are examples of_________.

are mechanical energy, thermal energy, chemical energy, electrical energy, electromagnetic energy, and nuclear energy.

What are the major forms of energy?

The kinetic energy of any moving object depends on its mass and speed. KE = 1/2 mv²

What factors does the kinetic energy of an object depend on?

is the ability to do work and it is transferred by a force moving an object through a distance.

What is Energy?

is potential energy that depends upon an object's height. This type of PE increases when an object is raised to a higher level.

What is gravitational energy?

is the energy of motion.

What is kinetic energy?

is energy that is stored as a result of position or shape.

What is potential energy?

is the energy stored in ATOMIC NUCLEI. 2types as nuclear FISSION and nuclear FUSION.

What is the Nuclear energy? how many types of the nuclear energy?

Chemical energy is converted into mechanical energy.

What type of energy is converted into mechanical energy when the gasoline is burned in the car's engine to move the car?

Batteries.

Which convert chemical energy to electrical energy, are used to operate portable CD players, flashlights, and calculators?

the motion of a pendulum, water falling in a waterfall, or a diver propelled by a diving board.

You can apply the law of conservation of energy to any mechanical process (any action) such as____________