What is energy?What is energy?Ability to do work or cause Ability to do work or cause changechange– Work: ability to move an object Work: ability to move an object

some distancesome distance

GeneralGeneral kinds of energy kinds of energyEnergy fits into one of two Energy fits into one of two categories: categories:

1.1. kinetic energy or kinetic energy or

2.2. potential energypotential energy

Kinetic energyKinetic energyEnergy of motionEnergy of motion–Also “released” Also “released” energy”energy”

Potential energyPotential energyStored energyStored energy–Energy at “rest”Energy at “rest”

Gravitational potential energyGravitational potential energy(G.P.E.)(G.P.E.)

Amount of potential energy based on the mass Amount of potential energy based on the mass and height of an objectand height of an objectThe higher the object is raised, the more potential The higher the object is raised, the more potential energy it hasenergy it hasThe more mass an object has, the more potential The more mass an object has, the more potential energy it hasenergy it has

Measuring Kinetic Energy Measuring Kinetic Energy

The faster the object, the greater the The faster the object, the greater the kinetic energykinetic energy– K.E. = ½ x mass x velocity (speed)K.E. = ½ x mass x velocity (speed)2 2

If the mass increases, kinetic energy If the mass increases, kinetic energy increases, but not as much as if the speed increases, but not as much as if the speed increasesincreases

What are the What are the

5 Specific F5 Specific Forms of Energyorms of Energy??

Mechanical energyMechanical energy

energy of energy of moving objectsmoving objects

Thermal (Heat) energyThermal (Heat) energy

Energy of Energy of moving moving atomsatoms

Electromagnetic energyElectromagnetic energy

Energy that Energy that travels in travels in waves waves through through spacespace

Chemical energyChemical energyEnergy that is Energy that is stored in stored in bonds between bonds between atomsatoms

Nuclear energyNuclear energyEnergy Energy released from released from the center of the center of an atom an atom – Fission and Fission and

fusion of fusion of atomsatoms

Forms of energy videoForms of energy video

Base your answers to questions 67 and 68 on the diagram below and on your knowledge of science. The diagram shows two students ready to dive into a pool.67 Explain why student B has more potential energy than student A. [1]_______________________68 Student A dives from the board into the water. Explain why student A’s kinetic energy decreases as the student enters the water. [1]______________________

Energy transformationsEnergy transformations

Change from Change from one one of the 5 of the 5 formsforms to to another another formform to “transfer” to “transfer” energyenergy

Base your answers to questions 69 through 72 on the illustration below and on your knowledge of science.The illustration shows a number of activities happening on a sunny day.

69 What is the original source of energy for all these activities? [1]___________________________70 Identify one activity in the diagram that requires the use of fossil fuels. [1]___________________________71 Identify one renewable resource shown in the diagram. [1]___________________________72 An energy transformation occurs when one form of energy is changed to another. Fill in the spaces below to describe an energy transformation that occurs as the children play baseball. [1]__________________________ is changed to _________________

Transform between kinetic and Transform between kinetic and potentialpotential

Pendulum: a Pendulum: a pendulum continuously transforms energy from kinetic to potential energy and back.

Pendulum animationPendulum animation

(Law Of) Conservation of Energy(Law Of) Conservation of Energy

Energy cannot be created or Energy cannot be created or destroyed, it is only transferreddestroyed, it is only transferred– Newton’s cradleNewton’s cradle– Bouncing ballBouncing ball– Energy Video: Conservation of EnergyEnergy Video: Conservation of Energy

E=mcE=mc2

– Einstein’s theory of relativity