Energy is not a substance! Energy has no direction! ENERGY: the _________________________________ _________________________________ When you do work on an object, you ___________________ energy to that object. Whenever work is done, energy is __________________________________ or __________________________________ to another system. Energy is also measured in ______________ Energy is not a substance! Energy has no direction!

Energy Systems Scientist study energy ___________________________. Boundaries define a system and are set by the observer. Systems may be ____________________________ CLOSED SYSTEM: the flow of energy into and out of a system is small enough that it can be ignored OPEN SYSTEM: the system exchanges energy with the space that surrounds it.

KINETIC ENERGY (KE or EK): Energy of a _________________________________due to the object’s motion. Kinetic energy depends on… ____________: more mass = more EK ________________: faster = more EK Kinetic Energy Equation Kinetic Energy = ½ x mass x speed squared EK = ½mv2

Potential energy is _________________________________ POTENTIAL ENERGY: Energy that an object has because of the __________________________________________________________________ Potential energy is _________________________________ There are many types of potential energy that we will cover… Gravitational Elastic Chemical Electrical Magnetic Potential Energy + Kinetic Energy = _________________________________

GRAVITATIONAL POTENTIAL ENERGY (GPE or EG): Energy an object has due to its relative height Gravitational potential energy (EG) depends on: ____________________: more mass = more EG ____________________: higher = more EG Gravitational free-fall ______________________: 9.81m/s2 (same everywhere on Earth) Gravitational Potential Energy Equation GPE = mass (m) x free-fall acceleration (g) x height (h) EG = _________________

Energy doesn’t appear out of nowhere. LAW OF CONSERVATION OF ENERGY: States that energy cannot be _______________________________ or ________________________________ Energy doesn’t appear out of nowhere. Whenever the total energy in a system increases, it must be due to energy that enters the system from an external source. Energy is __________________________ to another type or _______________________ to another system/object. Energy doesn’t disappear, but it can be changed to another form.

Energy Transfers and Transformations Example: GPE & KE Energy readily ______________ from one form to another. 12kg 7kg A) B) C) 7kg 5 m 5 m 3 m D) E) 7kg 5 m 7kg 5 m

Energy Transfers and Transformations Which one of the spheres has the most gravitational potential energy? Which one of the spheres has the most kinetic energy? What is the gravitational potential energy of the system in A? What is the kinetic energy of the system in D? Which sphere has kinetic and gravitational potential energy present?

Let the mass of the skier be 50kg and g= 10m/s2 Kinetic Energy (KE) Gravitational Potential Energy (PE) Kinetic Energy + Potential Energy = (Total) Mechanical Energy

Types of Energy 2 Main Energies we focus on: _________________________________ Gravitational Potential Energy (GPE) Other types of potential energy we study: Elastic Potential Electrical Potential Other types of nonmechanical energy we study: Thermal Sound Mechanical Energy at a larger level

ELASTIC POTENTIAL: Energy stored in any type of ______________________________ or __________________________________ material Such as a spring or a rubber band. CHEMICAL POTENTIAL: Energy stored due to the relative __________________________ of the atoms a substance contains and the _____________________________________ between the atoms. Fossil fuels Batteries Food Chemical Reactions

ELECTRICAL POTENTIAL Electricity is derived from the flow of _______________________________________(electrons ) Electric current running through appliances Electrostatic energy comes from a separation of _______________________________________________ Lightning bolt MAGNETIC POTENTIAL: Energy derived from the _______________________________________ of materials.

Electromagnetic Energy Flow of electrons (electricity) from a battery to a light bulb

ELECTROMAGNETIC (LIGHT): Energy in the form of _________________ that includes radio waves, microwaves, infrared waves, visible light, ultraviolet rays, x-rays, and gamma rays. Only energy that can travel through a vacuum (empty space) Living things ultimately get energy from the Sun. Plants use photosynthesis to turn the energy in sunlight into ________________________________________________ SOUND ENERGY

NUCLEAR (2 TYPES) NUCLEAR FUSION: _______________________________________ Process in Sun and other stars Can’t be used in power plants yet – too hard to control NO radioactive waste NUCLEAR FISSION: _______________________________________ Process in nuclear power plants and submarines Creates radioactive waste THERMAL: The kinetic energy of _________________________________________________ vibrating is related to heat and temperature. Lots of systems lose energy in the form of thermal energy More thermal energy = hotter = atoms move faster Less thermal energy = cooler = atoms move slower