Ryan Richardson and his SPECTACULAR Presentation on... WORK AND ENERGY

What exactly is “Work” ?? Work is the product of the magnitudes of the component of a force along the direction of displacement and the displacement.

Did you know that…. Work = Force x Distance ???

Fact… Work is done whenever a force acts on an object in the direction of the object’s motion. <<<<< LIKE THIS!!

However… NO MOTION… NO WORK!!! If the object is not in motion, there is no work in progress. In other words… NO MOTION… NO WORK!!!

Work is a scalar quantity; it has magnitude but no direction. Fact… Work is a scalar quantity; it has magnitude but no direction.

Can you measure “Work” ?? Of course you can!! As a matter a fact, work is measured in units called… *~*~*~Joules ~*~*~*

What else is there to know about a “Joule” ?? One joule of work is done on an object when the force is one newton and the displacement is one meter. The joule is a derived unit that can be expressed in terms of fundamental units. The symbol for a joule is (J).

What is the main thing you need to accomplish any kind of work??? ~*ENERGY*~ Duh!

Facts… The amount of energy a system possesses is equal to the amount of work the system can do. Work can be done only by the transfer of energy from one object or system to another.

Are there different types of energy? YES!! Energy is found in many forms such as: electromagnetic, chemical, mechanical, heat, nuclear, and sound.

Potential Energy The energy that an object has owing to its position or condition. The change in potential energy is equal to the work required to bring the object to its new position or condition from its original position or condition

Equations for Potential Energy /\PE = mg /\ h PE = mgh /\PE = W = F /\ S

Gravitational Potential Energy As an object is lowered from one position to another on earth, work is done by the earth’s gravitational field. This results in a decrease in gravitational potential energy The change in potential energy is equal to work done.

Elastic Potential Energy The energy stored in a spring when it is compressed or stretched.

What else about springs? The amount of potential energy stored in a spring is equal to the work done in stretching or compressing it from its original length.

Where do you use springs? Springs are used in toys, scales, mattresses, and shock absorbers. I hope that you knew that already…

What does Hooke’s law have to do with springs? The force (F), in newtons, needed to keep a spring compressed or stretched at a distance (x), in meters, is given by Hooke’s Law. Hooke’s Law is…… F = kx (K) is a property of the spring known as the spring constant. The unit for the spring constant is the newton/meter (N/m)

Is there anything else to know about Elastic Potential Energy? YUP! The elastic potential energy stored in a spring is equal to one-half the product of the spring constant and the square of the distance that the spring has been stretched from its original length. PE = (½)kx^2

Do you know anything about Kinetic Energy? Uh…. Yea… Kinetic energy is the energy an object has because of its motion. Like all forms of energy, it’s a scalar quantity. The symbol for kinetic energy is (KE)

Equations?? KE = (½) mv^2 Uh huh… KE = (½)mvf^2 – (½)mvi^2 W = KE + PE + Wf

Law Of Conservation of Energy The law of conservation of energy states that the total energy of a closed system remains constant. A closed system is one where no external work is done on or by the system. Energy can be converted within the system from one form to another, but the total amount of energy within the system cannot change.

Anything Else? Conservation of energy can also be illustrated by the swing of a pendulum. If no energy is lost due to friction or air resistance, the motion and conversion of energy from potential to kinetic back to potential continues forever.

Conservation Forces Forces, such as gravity, for which mechanical energy remains constant, are known as conservative forces. Forces, such as friction, that convert mechanical energy into internal energy and heat, are called non-conservative forces.

So…. ENERGY IS NEEDED TO DO WORK If you haven’t learned anything from this spectacular presentation and don’t remember anything…. Remember this…. ENERGY IS NEEDED TO DO WORK

Presentation Copyright 2006 by “R. Rich” Inc. Closing Credits Directed by : Ryan Richardson Co-Directed by : Ryan Richardson Researched by : Ryan Richardson Designed by : Ryan Richardson Written by : Ryan Richardson Also Written by : Ryan Richardson Sponsored by : Ryan Richardson Credits by : Ryan Richardson Presentation Copyright 2006 by “R. Rich” Inc. Duplication of any part of this presentation will be handled to the highest extent if necessary. Thank You.