What is energy?

Energy is a property of objects, transferable among them via fundamental interactions, which can be converted into different forms but not created or destroyed.

What is energy? Energy is a property of objects, transferable among them via fundamental interactions, which can be converted into different forms but not created or destroyed. Example/ PE = Potential Energy = Energy of Position Gravitational PE Spring PE

Gravitational Potential Energy = = mgh = (mass)(gravity)(height)

Gravitational Potential Energy = = mgh = (mass)(gravity)(height) All energy is measured using the joule (in SI)

Gravitational Potential Energy = = mgh = (mass)(gravity)(height) All energy is measured using the joule (in SI) How much is 1 joule?

Gravitational Potential Energy = = mgh = (mass)(gravity)(height) All energy is measured using the joule (in SI) How much is 1 joule? 1 joule = mgh = (0.1 kg)(~10 m/s 2 )(1 m) 0.1 kg = 3.5 oz

Gravitational Potential Energy = = mgh = (mass)(gravity)(height) All energy is measured using the joule (in SI) How much is 1 joule? 1 joule = mgh = (0.1 kg)(~10 m/s 2 )(1 m) 0.1 kg = 3.5 oz

Gravitational Potential Energy = = mgh = (mass)(gravity)(height) Where do you measure h from?

Expanding Universe: Sum of radiation&mass (positive) and gravitational potential energy (negative) = zero (?)

Forms of Energy: KE = Kinetic Energy (motion) = = ½ mv 2 = ½ (mass)(velocity) 2

Forms of Energy: KE = Kinetic Energy (motion) PE = Potential Energy (position) ME = Mechanical Energy = KE + PE = ½ mv 2 + mgΔh

Forms of Energy: KE = Kinetic Energy (motion) PE = Potential Energy (position) ME = Mechanical Energy = KE + PE = ½ mv 2 + mgΔh What happens, eventually?

Forms of Energy: KE = Kinetic Energy (motion) PE = Potential Energy (position) ME = Mechanical Energy = KE + PE = ½ mv 2 + mgΔh What happens when you bounce a ball?

During every bounce, some amount of energy is lost to heat, usually by internal or external friction

High-speed golf ball impact:

Baseball deforming during impact:

Other Forms of Energy: Thermal Energy Chemical Energy Nuclear Energy (Mass) Electrical Energy Physical Wave Energy (sound, water waves, seismic waves) Radiant Energy (electromagnetic radiation; “light”)

Thermal energy is a measure of the total kinetic energy of the particles of a substance.

Temperature is a measure of the average kinetic energy of the particles of a substance.

Thermal energy: More Less Temperature: Same Same

Heat is the transfer of thermal energy

Work is the transfer of mechanical energy: W = F d = (Force x Distance) F = ma = (Mass x Acceleration)

Law of conservation of energy: During a conversion from one form of energy into another, the total amount of energy doesn’t change During every energy conversion, some amount of energy is lost to heat, usually by internal or external friction

Law of conservation of energy: During a conversion from one form of energy into another, the total amount of energy doesn’t change

Other Forms of Energy: Thermal Energy Chemical Energy Nuclear Energy (Mass) Electrical Energy Physical Wave Energy (sound, water waves, seismic waves) Radiant Energy (electromagnetic radiation; “light” waves)

World Energy Consumption, by Source (2013)

[EIA = Energy Information Administration]

World Energy Consumption, by Source (1 exajoule = 1 EJ = 1 quintillion joules = j)

(1 Quad = Quadrillion British thermal units = = exajoules = EJ)

Where in the world is the fastest growth in energy production?

How much of U.S. energy is imported?

Is U.S. per capita energy use increasing or decreasing?

Historical World Energy Production (Gboe = billion barrels of oil equivalent)

What is most U.S. energy used for?

What are the energy sources for transportation?

What is the efficiency of U.S. cars and trucks?

What are the major energy sources produced in the U.S.?

Where does your electricity come from?