Energy

What is Energy? Energy is the ability to do work. Measured in Joules. 5 types of Energy:

Mechanical Energy Energy of motion. Like a waterfall, wind, a car, a bike, etc. Sound is also Mechanical Energy. What is in motion?

Mechanical Energy

Heat Energy Heat is internal motion of atoms. Faster atoms move, or the more atoms there are moving, the more heat energy. Heat energy can cause change in Temperature and phase (solid, liquid and gas)

Chemical Energy Energy of bonds between atoms. Like food energy released when food is digested. Fire!

Burning of Methane

Electromagnetic Energy Moving Electrons. Batteries change chemical energy into electricity. Magnets, compass Light, X-rays, Radio Waves

Electromagnetic Spectrum

Nuclear Energy Energy stored in the nucleus of atoms.

Nuclear Fission When atoms are split, energy is released.

Nuclear Fusion When atoms are joined by nuclear fusion, energy is released

E=mc2 "It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing — a somewhat unfamiliar conception for the average mind. Furthermore, the equation E = mc², in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa. The mass and energy were in fact equivalent, according to the formula mentioned before. This was demonstrated by Cockcroft and Walton in 1932, experimentally."

Energy of a Person E=mc2 M=mass of Person= 59 kg C=speed of light= E=? 299,792,458 m / s  E=? 5,302,655,554,547,224,076 J or 5.3x1018 J

Kinetic Energy Energy of “things” in motion. Mechanical, Electromagnetic, and heat are all kinetic. K.E. = ½ mv2

Potential Energy Stored Energy, energy of position. Chemical and Nuclear are potential energy. Gravitational Potential Energy P.E. = mgh P.E. = mass x gravity x height

Energy Conversions Law of Conservation of Energy – Energy can not be created or destroyed, it can only change from one form to another.

Energy Conversions All forms of energy can be converted to other forms. For example – the sun converts nuclear energy into electromagnetic which is then converted into chemical by plants. We then eat the plants and convert the chemical energy into heat for our bodies and mechanical energy of our movement.