15.1 Energy and Its Forms P.6.PS.14 Solve problems by using formulas for gravitational potential and kinetic energy: 221 mvKE PE=mgh P.6.PS.13 Design an

15.1 Energy and Its Forms

P.6.PS.14 Solve problems by using formulas for gravitational potential and kinetic energy:

221mvKE

PE=mghP.6.PS.13

Design an experiment to show conversion of energy: mechanical (potential and kinetic) chemical thermal sound light nuclear

P.8.PS.2 Calculate electrical power using current and voltage: IVP

C.2.PS.3 Relate thermal expansion to the kinetic theory

P.5.PS.1 Distinguish among thermal energy, heat, and temperature

P.5.PS.2 Calculate changes in thermal energy using: TmcqpΔ=

Where = heat energy, = mass, = specific heat, qmpcTΔ = change in temperature

Students start on opener slide with correct date and continue from there. Watch all video as well.

15.2 Energy Conversion and Conservation

Thursday - February 18, 2010No opener today. Just get your stuff. CAPS schedule today.Pick up computers and test answers from yesterday.

Get pizza party orders & money for tomorrow’s pizza party....

CW: Finish essay portion of test...CW: Video Project for Egg Drop

Make a script for the last portion.

See instructions for uploading video.


Opener #9 - Friday - February 19, 2010 - Pick up computers...Use complete sentences to answer the following.1. Answer Sect. 14.1 assessment questions pg. 416 #1-4. DON’T FORGET PIZZA PARTY TODAY AT LUNCH! REMIND 3RD PERIOD STUDENTS IF YOU SEE THEM! See me about $3 after we start notes.A) TURN in computer game lab from ch. 12-13 (the one with the sports; be sure you answered questions on the back...) I know you didn’t have time to do all of the games on the back. TURN IN BOX.B) TURN in your chapter 12 problems worksheet (12 problems that you were to make corrections to after we graded to help you prepare for the test...) C) Check and make sure you have turned in LABS: 10 station lab, motion detector lab, siphon lab, etc. CHECK Pinnacle. Turn in Box. Last chance to get full credit... (See no name papers if you need to or a couple of assignments if you do not find... See me if you combined graphs in groups on motion detector lab and didn’t get score from graphs. You were supposed to still answer questions... but will count this time as a group since graphs were to do together if printed.... * CW: NOTES 15.1 AND FINISH iMovie - clarify importance of concepts being discussed....


Electrical power

P = IV amps * volts = Watts for what we are doing...

Main article: Electric power

[edit]

Instantaneous electrical power

The instantaneous electrical power P delivered to a component is given by

P(t) = I (t) times V(t)

where

P(t) is the instantaneous power, measured in watts (joules over second)

V(t) is the potential difference (or voltage drop) across the component, measured in volts

I(t) is the current through it, measured in amperes

Homework Project...due next Wednesday.Find 10 different type electronics, appliances, or engines in your home and make a list of these and the power they use. Most of these will be in Watts. You can also calculate electrical power with the following formula.

http://en.wikipedia.org/wiki/Electric_power

http://en.wikipedia.org/w/index.php?title=Power_(physics)&action=edit&section=4

http://en.wikipedia.org/wiki/Watt

http://en.wikipedia.org/wiki/Watt

http://en.wikipedia.org/wiki/Joule

http://en.wikipedia.org/wiki/Second

http://en.wikipedia.org/wiki/Potential_difference

http://en.wikipedia.org/wiki/Volt


In an avalanche, a mass of loose snow, soil, or rock suddenly gives way and slides down the side of a mountain.

The avalanche releases a great amount of energy.


How are energy and work related?Energy is the ability to do work.

Energy and Work

Work is a transfer of energy.


Work and energy are closely related. • Energy is known by the changes it causes. • Work is done when a force moves an object

through a distance. Energy is transferred by a force moving an object through a distance.

• Both work and energy are typically measured in joules (J).

Energy and Work


Energy has different forms. A. The sun gives off energy in the form of heat and

light.

Energy and Work



light.

B. Plants convert sunlight into food.

Energy and Work



light.

B. Plants convert sunlight into food.

C. People convert food energy into muscle movement.

Energy and Work


What factors does the kinetic energy of an object depend on?The energy of motion is called kinetic energy.coming from the Greek word meaning “moving”.

Kinetic Energy

The kinetic energy of any moving object depends upon its mass and speed.


• Doubling the mass in the formula doubles the kinetic energy.

• Doubling the speed or velocity quadruples the kinetic energy.

Kinetic Energy


Calculating Kinetic Energy - RECORD!!!A 0.10-kilogram bird is flying at a constant speed of 8.0 m/s. What is the bird’s kinetic energy?

Kinetic Energy


Read and UnderstandWhat information are you given?

What unknown are you trying to calculate?

Kinetic Energy


Read and UnderstandWhat information are you given?

What unknown are you trying to calculate?

Kinetic Energy


Plan and SolveWhat equation contains the given quantities and the unknown?

Substitute the known values in the formula for KE.

Kinetic Energy


Plan and SolveWhat equation contains the given quantities and the unknown?

Substitute the known values in the formula for KE.

Kinetic Energy


Look Back and CheckIs your answer reasonable?

Kinetic Energy


Look Back and CheckIs your answer reasonable?

It seems reasonable, because the bird has a low mass, so it would not have much kinetic energy.

Kinetic Energy


1. A 70.0-kilogram man is walking at a speed of 2.0 m/s. What is his kinetic energy?

Answer:

Kinetic Energy


1. A 70.0-kilogram man is walking at a speed of 2.0 m/s. What is his kinetic energy?

Answer:

KE = (0.50)(70.0 kg)(2.0 m/s)2 = 140 J

Kinetic Energy


2. A 1400-kilogram car is moving at a speed of 25 m/s. How much kinetic energy does the car have?

Answer:

Kinetic Energy


2. A 1400-kilogram car is moving at a speed of 25 m/s. How much kinetic energy does the car have?

Answer:

= (0.50)(1400 kg)(25 m/s)2

= 440,000 J

Kinetic Energy


3. A 50.0-kilogram cheetah has a kinetic energy of 18,000 J. How fast is the cheetah running? (Hint: Rearrange the equation to solve for v.)

Answer:

Kinetic Energy


3. A 50.0-kilogram cheetah has a kinetic energy of 18,000 J. How fast is the cheetah running? (Hint: Rearrange the equation to solve for v.)

Answer:

Kinetic Energy


How is gravitational potential energy determined?Potential energy is energy that is stored as a result of position or shape.

Potential Energy

An object’s gravitational potential energy depends on its mass, its height, and the acceleration due to gravity.


When this musician pulls the string of her cello to one side, the string is stretched and gains potential energy.

Potential Energy


The musician adds energy to the cello string by plucking it.

• The energy stored in the stretched string is potential energy.

• The stored energy is converted into kinetic energy when the string is released and it vibrates.

Potential Energy


Gravitational Potential EnergyPotential energy that depends upon an object’s height is called gravitational potential energy. This type of potential energy increases when an object is raised to a higher level.

Potential Energy


This diver has gravitational potential energy as she stands at the end of a diving board.

She gained the potential energy by doing work—by climbing up the steps to the diving board.

Potential Energy


Click on the following web site and click on “Play” and/or “Step”In your opener, write out the answers to the following questions. Complete sentences are not needed.

http://www.teachersdomain.org/resource/hew06.sci.phys.maf.rollercoaster/click on View (not download). If this gives you a problem logging on, let me know. I may have to show it on my screen.

Pay attention to the transfer of energy along the roller coaster ride.RELATED TO ROLLER COASTER FLASH ANIMATION ABOVE...1. Where was potential energy the greatest? 2. Where was kinetic energy the greatest?3. At what point was the velocity the greatest? What was the value of the fastest velocity?4. How does this speed relate to potential or kinetic energy?

http://www.teachersdomain.org/resource/hew06.sci.phys.maf.rollercoaster/


• The unit for mass is kilograms.• The unit for height is meters.• Acceleration due to gravity, g, has a value in

SI units of 9.8 m/s2 on Earth.• The unit for gravitational potential energy is

joules.

Potential Energy


Height is measured from the ground or floor or some other reference level.

Doubling either the mass of the object or its height doubles its gravitational potential energy.

Potential Energy


What is the potential energy relative to the water surface of a diver at the top of a 10.0-meter-high diving platform. Suppose she has a mass of 50.0 kilograms. - RECORD EXAMPLEPE = mgh= (50.0 kg)(9.8 m/s2)(10.0 m)

= 4900 kg•m2/s2 = 4900 J

Potential Energy


QuickTime™ and a decompressor

are needed to see this picture.

Watch the following and look for changes in potential and kinetic energy and designs with regard to momentum..


Elastic Potential EnergyThe potential energy of an object that is stretched or compressed is known as elastic potential energy. Something that is elastic springs back to its original shape after it is stretched or compressed.

Potential Energy


Examples:

A compressed bicycle shock absorber and a wound-up toy robot both have elastic potential energy.

Potential Energy


What are the major forms of energy?

Forms of Energy

The major forms of energy are mechanical energy, thermal energy, chemical energy, electrical energy, electromagnetic energy, and nuclear energy.


FORMS OF ENERGY.... Watch video first... List types of energy in column of notes.

QuickTime™ and a decompressor

are needed to see this picture.


All energy can be considered to be one of three forms:

• kinetic energy,• potential energy, and• energy in fields such as those produced by

electromagnetic waves.

Each of these forms of energy can be converted into other forms of energy.

Forms of Energy


Mechanical EnergyThe energy associated with the motion and position of everyday objects is mechanical energy. Mechanical energy is the sum of an object’s potential energy and kinetic energy. (PE and KE)

Forms of Energy


Thermal EnergyThe total potential and kinetic energy of all the microscopic particles in an object make up its thermal energy. When an object’s atoms move faster, its thermal energy increases, and the object becomes warmer.

Forms of Energy


This molten metal is extremely hot. It contains a great deal of thermal energy.

Forms of Energy


Chemical EnergyChemical energy is the energy stored in chemical bonds.

When bonds are broken, the released energy can do work. All chemical compounds, including fuels such as coal and gasoline, store energy.

Forms of Energy


This family is using the chemical energy of burning wood to produce thermal energy for heating marshmallows.

Forms of Energy


Electrical EnergyElectrical energy is the energy associated with electric charges.

Electric charges can exert forces that do work.

Forms of Energy


Electromagnetic EnergyElectromagnetic energy is a form of energy that travels through space in the form of waves.

Visible light and X-rays are examples of electromagnetic energy.

Forms of Energy


A. Lightning bolts transfer electric charge.

B. Galaxies are giant structures in space that typically contain billions of stars. The stars give off enormous amounts of electromagnetic energy.

Forms of Energy


Nuclear EnergyThe nucleus of an atom is held together by strong and weak nuclear forces, which can store an enormous amount of potential energy.

• The energy stored in atomic nuclei is known as nuclear energy.

• Nuclear fission releases energy by splitting nuclei apart.

• Nuclear fusion releases energy when less massive nuclei combine to form a more massive nucleus.

Forms of Energy


Assessment Questions - See if you can get these correct.1. How are work and energy related?

a. Energy is the rate of doing work.

b. Work is a form of energy.

c. Work is the transfer of energy.

d. Energy is created by work.


Assessment Questions

1. How are work and energy related? a. Energy is the rate of doing work.

b. Work is a form of energy.

c. Work is the transfer of energy.

d. Energy is created by work.

ANS: C



2. A moving object with a mass of 10 kg has 320 J of kinetic energy due to its motion. How fast is the object moving?a. 64 m/sb. 32 m/sc. 8 m/sd. 10 m/s



2. A moving object with a mass of 10 kg has 320 J of kinetic energy due to its motion. How fast is the object moving?a. 64 m/sb. 32 m/sc. 8 m/sd. 10 m/s

ANS: C



3. Which of these is an example of elastic potential energy?a. a bow prepared to release an arrow

b. a rubber ball thrown into the air

c. a book about to fall from a table

d. a truck pulling a trailer



3. Which of these is an example of elastic potential energy?a. a bow prepared to release an arrow

b. a rubber ball thrown into the air

c. a book about to fall from a table

d. a truck pulling a trailer

ANS: A



4. A small airplane and a helicopter have identical masses. If the airplane’s altitude compared to the ground is three times that of the helicopter, how much more gravitational potential energy does the airplane have than the helicopter?

a. 0.333 times as much

b. 3 times as much

c. 6 times as much

d. 9 times as much



4. A small airplane and a helicopter have identical masses. If the airplane’s altitude compared to the ground is three times that of the helicopter, how much more gravitational potential energy does the airplane have than the helicopter?

a. 0.333 times as much

b. 3 times as much

c. 6 times as much

d. 9 times as much

ANS: B



5. The energy stored in the bonds between atoms of a compound is called a. electromagnetic energy.

b. chemical energy.

c. atomic energy.

d. thermal energy.



5. The energy stored in the bonds between atoms of a compound is called a. electromagnetic energy.

b. chemical energy.

c. atomic energy.

d. thermal energy.

ANS: B


Be sure you have turned in LABS: siphon lab, 10 station lab, motion detector lab, computer game review lab & ch. 12 problems handout sheet.

BE SURE YOU ARE ANSWERING QUESTIONS RELATED TO PROJECT BY PULLING UP THE QUESTION AND INSTRUCTIONS THAT YOU SHOULD BE INCLUDING IN YOUR FINAL SCENES OF YOUR VIDEO. THIS IS THE MOST IMPORTANT PART OF THE VIDEO. WRITE A SCRIPT AND DO THIS BEFORE YOU WORRY ABOUT THE EXTRA “BELLS AND WHISTLES”. I’D LIKE THESE TO BE READY TO UPLOAD TO A MOVIE BY MONDAY...

http://podcast.bryantschools.org/users/dvann is the web site link for pulling the instructions for the Egg drop video. Have one partner do this while the other partner(s) work on the video portion and help each other write and record your last video script scene(s)...

Ask for help if you need it. You may have to come to me if I am helping other groups.You may work on your video before school, lunch, or after school also. You can also use the closet area for recording the last portion to help find quieter areas but must have script.

Documents

15.1 Energy and Its Forms P.6.PS.14 Solve problems by using formulas for gravitational potential and kinetic energy: 221 mvKE PE=mgh P.6.PS.13 Design an