Energy Chapter 4

What is Energy? - the ability to do work or cause change. * When you do work on an object, some of your energy is transferred to that object * When energy is transferred, the object upon which the work is done gains energy.

Energy Cont’d... Unit for energy = Joules Figure 1 – pg 109 adfffdafasdf

Types of Energy Kinetic: energy an object has due to its motion Depends on: speed and mass *Faster an object moves = more kinetic energy *More mass = more kinetic energy 𝐾𝐸= 1 2 𝑥 𝑀𝑎𝑠𝑠 𝑥 𝑆𝑝𝑒𝑒𝑑2 ~ Figure 2 pg. 110 Potential Energy: Energy that results from the position or shape of an object *Energy that has the POTENTIAL to do work

Types of Potential Energy ~Gravitational Potential Energy: potential energy related to height. *GPE = Weight x Height ~ Elastic Potential Energy: potential energy due to shape (compressed or stretched)

Figure 3 and 4 pg 112-113

Forms of Energy Mechanical Energy – energy associated with motion, position, or shape of an object Mechanical Energy = PE + KE

Figure 1 – pg 115

APPLY IT – pg 116

Types of Energy associated with Particles Nuclear Energy Thermal Energy Electrical Energy Electromagnetic Energy Chemical Energy

Nuclear Energy Potential energy stored in the nucleus of an atom Nuclear fission – nucleus splits Nuclear fusion – nuclei of atoms fuse or join together Figure 2 pg 117

Thermal Energy The total kinetic and potential energy of the particles in an object. Higher the temperature (movement of particles) = higher thermal energy

Electrical Energy Energy from Electric charges Can be either potential or kinetic energy depending if charges are in motion

Electromagnetic Energy Energy that travels through space in waves Examples: microwaves, X-rays, Infared (heat) waves, radio waves

Chemical Energy Potential energy stored in chemical bonds. Chemical bonds – hold atoms together When bonds break – energy is released

Figure 3 pg 118-119

Energy Transformation and Conservation ALL FORMS OF ENERGY CAN BE TRANSFORMED INTO OTHER FORMS OF ENERGY. Energy transformation: a change form one form of energy to another

Types of Transformation Single: where one form transforms into another form to get work done Ex – electrical to thermal (toaster) - Chemical to mechanical (body breaking down food to use to move muscles) Multiple: series of transformations happen in order to do work. Ex: mechanical thermal chemical thermal electromagnetic Strike a match fire heat causes bonds to break heat again see light from flame

Apply it - 121 chemical kinetic chemical Nuclear electromagnetic thermal chemical electromagnetic

Figure 1 and figure 2 pg. 122 Gravitational potential energy The ball is covering more distance in equal time intervals, o its speed is increasing and therefore kinetic energy increases. Kinetic Energy

Figure 3 pg 123 Kinetic Energy Elastic Energy Kinetic Energy Gravitational potential energy Kinetic Energy

Law of Conservation of Charge Law states that Energy can not be created or destroyed. The amount of energy is the same before and after transformation Pg 124-125