ENERGY!

Question: What is Energy?

Answer: The ability to do work (move something) or cause change in a system.

• Energy is NOT an object, but something an object can possess due to its condition or state.

• All forms of energy are SCALAR. We are only concerned with the amounts of energy objects possess or transfer.

Energy!

Energy comes in many forms, but there are two basic categories of energy:

Is energy objects possess due to their condition or state. There are three forms of

mechanical energy we will be concerned with in this course:

Potential EnergyKinetic EnergyWork Energy

Is radiant energy, such as

visible light, microwaves,

radio waves and X-Rays. (These we will study

later!)

Mechanical Energy!

- ET is the sum of all the different forms of mechanical energy an object or system has at any given time.

- For our purposes, ET consists of the 3 basic forms of mechanical energy:

The total mechanical energy of an object or system is symbolized by

ET

Mechanical Energy!

There are two basic types of Potential Energy (PE) we will study in this course:

Is energy objects possess due to their

position (height) above the earth’s surface .

Is energy objects possess due to energy stored when forces are

applied to an elastic material, such as a spring.

Gravitational (PE)

Elastic (PES)

Mechanical Energy!In our first lab activity, we will be exploring how energy transforms from one form of energy to another. You need to know the units of energy are Joules (J) or Newton-meters (Nm). You also need the following equations:

PE = mgh

KE = ½ mv2

Where: m = mass m = mass g = gravitational acceleration v =

velocity h = height

Mechanical Energy!When PE or KE is changed in order to move or deform an object, the energy that gets used or transformed is called “WORK.” The symbol for work is:

Work is energy and has the same units as all other forms of energy, J or Nm.

The equation for work is also necessary for this activity:

W = Fd

W

Where: F = Force applied

d = displacement of the object