Mechanical+Energy

=Mechanical Energy and Work =

 In order to understand the concept of mechanical energy it is important to grasp the idea of work. It is said that work is done on an object when a force is applied. A force can be defined as a push or a pull on an object therefore work is done when a force causes an object to move. For example, if you hold your book over your head is work being done? You are getting tired because you have to use energy to hold the book but the book is not moving over a distance. If the book is still then no work has been done because W= F x d; or work is equal the force applied to an object over a distance. Now, if you lift a book off the table then work has been done, right? Right, because you applied a force to move the book over a distance. How much work is done depends on how far you moved the book and with how much effort and is measured in Joules (J). Check out the [|Glenbrook website] for more examples.

 Now that we understand the idea of work we can examine mechanical energy. Mechanical energy is determine based on the relative position of an object. It can be determined by the sum of [|potential] energy and [|kinetic] energy. The ability to do work is mechanical energy. This work can be done with the use of simple or compound machines. The advantage of using a machine is known as mechanical advantage.  Mechanical advantage of a system can be determine in two ways.

==== ====

Information for Project:



Syllabus for Mechanical Energy:
1. Review Simple Machines- A majority of this should be familiar info from previous science classes 2. LEVERS: Examine the various levers and complete activity. You can also access this from the network folders and drop in my drop box using hand-in robot.

3. Determine Mechanical Advantage Activity for various machines. 4. Examine various tools for MA.

5. Quiz on MA and Simple Machines

6. GEARS- What we are examining here are how gears can either multiply speed or force. Use the gear boxes to determine the difference. Determine the force/speed trade off for gears [|Gears] Using Comic Life or Omni Graffle explain the series of four questions on the [|leverage exercise]. Once complete submit your activity with your name and period in my drop box.

7. Pulleys- Our last simple machine activity will be using pulleys to make work easier. Determine the mechanical advantage of the pulleys in each of these activities.

8.Efficiency of machines:. Use the powerpoint and note sheet to help you understand efficiency of machines. To measure efficiency, you need to remember that you lose energy to friction. To determine how efficient a machine is you use must measure the amount of work out/work.

9. For a review of machines and mechanical advantage check out this 12 minute video.

====Quia practice quiz will help you review key concepts and practice problems for the test! ====

Marking Period Project= Rube Goldberg Device -Here are some cool projects:[|Rube Goldberg Project Examples] -much more complex then what we will do but awesome ideas.