Chapter 4Chapter 4

EnergyEnergy

What is energy?What is energy?

Def:Def: ability to cause ability to cause __________________________________

Every change involves Every change involves ______________________________________________

Different FormsDifferent Forms

__________________________________________________ _______________________ – stored in _______________________ – stored in

food, involved in reactionsfood, involved in reactions _______________________– gives off_______________________– gives off _______________________ – heat_______________________ – heat Same thing just different formsSame thing just different forms

Kinetic EnergyKinetic Energy

Def:Def: energy of a __________________ object energy of a __________________ object Depends on _________________ and Depends on _________________ and

__________________________________

Kinetic energy Kinetic energy (Joules) = (Joules) = 11 massmass (kg) x [ (kg) x [speedspeed (m/s)](m/s)]22

22

KE = KE = 11 mv mv22

22 SI unit for energy is ______________________SI unit for energy is ______________________

Practice!Practice!

What is the kinetic energy of a .15 kg What is the kinetic energy of a .15 kg baseball moving at 40 m/s.baseball moving at 40 m/s.

A car moving at a speed of 20 m/s has a A car moving at a speed of 20 m/s has a kinetic energy of 300,000 J. What is the kinetic energy of 300,000 J. What is the car’s mass?car’s mass?

Potential EnergyPotential Energy

Even ______________________ objects Even ______________________ objects have energyhave energy

_____________________ in the object, _____________________ in the object, has potential to changehas potential to change

Def: Def: ________________ energy________________ energy

Elastic Potential EnergyElastic Potential Energy

Def:Def: ___________________ energy by ___________________ energy by something that can _________________ something that can _________________ or compressor compress

Stretched rubber band – elastic Stretched rubber band – elastic potential energy potential energy _________________ _________________ energyenergy

Chemical Potential EnergyChemical Potential Energy

Def:Def: energy stored in energy stored in _____________________ bonds_____________________ bonds

Food, gasoline, etc.Food, gasoline, etc.

Gravitational Potential Gravitational Potential EnergyEnergy

Def:Def: stored energy by objects due to stored energy by objects due to position ___________________ earth (able to position ___________________ earth (able to fall)fall)

Practice!Practice!

Find the height of a .15 kg baseball Find the height of a .15 kg baseball that has a GPE of 73.5 J.that has a GPE of 73.5 J.

Find the GPE of a .3 kg coffee mug Find the GPE of a .3 kg coffee mug on a 1-m high counter.on a 1-m high counter.

What could you do to change GPE?What could you do to change GPE? Change _______________ or __________Change _______________ or __________

Section 2Section 2

Conservation of EnergyConservation of Energy

Changing Forms of EnergyChanging Forms of Energy

Changing electrical energy –> electricity –Changing electrical energy –> electricity –> light and heat energy> light and heat energy

Energy is ______________________ changing Energy is ______________________ changing formsforms

Transforming Chemical Transforming Chemical EnergyEnergy

Cars – ______________________ energy Cars – ______________________ energy transformationstransformations

Spark plug – ____________________ – engine Spark plug – ____________________ – engine - wheels- wheels

Transforming Chemical Transforming Chemical EnergyEnergy

_________________ plants – take in _________________ plants – take in

_____________________ and transform _____________________ and transform to chemical energy in plantsto chemical energy in plants

Mechanical EnergyMechanical Energy

Def:Def: total amount of ________________ total amount of ________________

and ______________________ energyand ______________________ energy

Mechanical Energy = Potential + Mechanical Energy = Potential + KineticKinetic

Falling ObjectsFalling Objects

As potential As potential kinetic, kinetic, __________________ __________________ energy stays sameenergy stays same

Potential _________ = Potential _________ =

kinetic _____________kinetic _____________

Projectile MotionProjectile Motion

Mechanical energy remains Mechanical energy remains __________________________________

Still see _________________________ of Still see _________________________ of energyenergy

SwingingSwinging

Best part is falling Best part is falling from highest pointfrom highest point

High GPE = Low KEHigh GPE = Low KE

Describe Describe transition…transition…

Law of Conservation of Law of Conservation of EnergyEnergy

Def:Def: ___________________ can not be ___________________ can not be created or destroyedcreated or destroyed

Energy just changes _________________Energy just changes _________________ All energy in the All energy in the

________________________ does not ________________________ does not changechange

Energy in = Energy outEnergy in = Energy out

Is energy always Is energy always conserved?conserved?

Swinging – you eventually will stop – Swinging – you eventually will stop – where does all the energy go?where does all the energy go?

____________________ – air resistance = ____________________ – air resistance = thermal energythermal energy

Human Body – Energy Human Body – Energy RelationsRelations

What forms of energy are in your What forms of energy are in your body?body?

Conservation of energy still trueConservation of energy still true Food, fat = __________________ energyFood, fat = __________________ energy Activity = ___________________ energyActivity = ___________________ energy Calorie 1C = 4,184 JCalorie 1C = 4,184 J

Chapter 6 Section 1Chapter 6 Section 1

Temperature and HeatTemperature and Heat

Matter in MotionMatter in Motion

______________________ is made of tiny ______________________ is made of tiny

particles in _______________________ motion particles in _______________________ motion have kinetic energy have kinetic energy

Faster = ________________ kinetic energyFaster = ________________ kinetic energy

TemperatureTemperature

Def:Def: measure of measure of ________________________________ kinetic energy of particleskinetic energy of particles

High Temp. = ______________ High Temp. = ______________ EnergyEnergy

Low Temp. = _______________ Low Temp. = _______________ EnergyEnergy

Unit Unit Kelvin Kelvin

Thermal EnergyThermal Energy

_____________________ between air and _____________________ between air and butter particles increase energy of butter butter particles increase energy of butter = ____________________ temperature= ____________________ temperature

Def: Def: ________________ of kinetic and ________________ of kinetic and potential energy of particles in objectpotential energy of particles in object

Thermal EnergyThermal Energy

As temp ___________________ = thermal As temp ___________________ = thermal energy increasesenergy increases

If object has MORE __________________ and at If object has MORE __________________ and at the same temp. has HIGHER thermal energythe same temp. has HIGHER thermal energy

HeatHeat

Is your seat toasty?Is your seat toasty? Def:Def: ________________ energy that ________________ energy that

flows from something at a flows from something at a _________________ temp to a lower _________________ temp to a lower temptemp

Unit: JouleUnit: Joule

Beachin’ it up!Beachin’ it up!

How can there be extreme How can there be extreme differences in temperature from air, differences in temperature from air, _______________ and water?_______________ and water?

Sun rays are the same why different Sun rays are the same why different temp?temp?

Sand heats up ______ times faster Sand heats up ______ times faster than waterthan water

Specific HeatSpecific Heat

Specific Heat:Specific Heat: heat needed to raise heat needed to raise ___________ of material by 1___________ of material by 1CC

Water as a CoolantWater as a Coolant

It’s _______________ specific heat – absorb a It’s _______________ specific heat – absorb a

lot of heat ________________ changing temp lot of heat ________________ changing temp muchmuch

______________ bonds have to be broken ______________ bonds have to be broken before particles move really fastbefore particles move really fast