Energy Notes

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Energy Notes-

Learning Targets - I can…

differentiate between kinetic and potential energy.

identify different types of energy.

describe ways in which energy can be lost.

calculate potential and kinetic energy of a system.

describe units used to quantify energy.

state the law of conservation of energy.

describe examples of energy conversions.

Is ENERGY involved in the following things?

Chewing gum

Wind blowing

Water flowing down a creek

Taking a test

Thinking about your boyfriend

Looking at the clock

Sun shining through the window

Every CHANGE that occurs requires energy.

Energy = the ability to cause change or do work.

Different forms or energy:

Mechanical

Thermal

Radiant

Electrical

Chemical

Nuclear

Sound

Gravitational

Mechanical – Energy associated with motion.

Thermal (Heat) – Energy associated with internal motion of molecules.

Chemical – Energy required to bond atoms together.

Electromagnetic – Energy of moving electrical charges that do work.

Nuclear – Energy stored at the nucleus of atoms.

Kinetic Energy:

= the energy of motion.

(the energy a moving object has because of its motion)

KE = ½ mv²

Standard unit is the Joule

What happens to KE when we double the mass or velocity of the object?

What happens if you double the mass?

KE = ½ (1 kg) (1 m/s)2

KE = ½ or .5 J

KE = ½ (2 kg) (1 m/s) 2

KE = 1 J

Potential Energy:

Potential means STORED energy.

Energy that is built-up before an object is in motion.

PE = mgh

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Example Problems:

1) Electrical or electromagnetic energy occurs when there is ___?__. (a type of kinetic energy)

a. a sharp change in temperature

b. a change in a substance due to a chemical reaction

c. a flow of charge ions or electrons through a current

d. an atomic reaction

2) Energy can only be ___?___.

a. converted from one form of energy to another form of energy

b. electrical or mechanical

c. positive or negative

d. created and destroyed