Name:______

Simply Machines!!!

Learning Objectives:

·  List the general steps of the engineering design process.

·  Think critically about the importance of the machines you encounter in life.

·  Use your knowledge of simple and compound machines to design and build a small Rube Goldberg machine.

(Log onto http://www.rube-goldberg.com/ to view a variety of Rube Goldberg Machines)

Introduction:

We have been learning about simple and compound machines, calculating mechanical advantage and thinking about machines as a part of society. What is a simple machine? A simple machine makes work easier for people. We also know that engineers build complex machines upon a foundation of knowledge of simple machines. Now we will look at how all of these things that we have been studying come together, as we take on the role of the engineer who designs the machines. We are not going to design just any machine though; we are going to invent a Rube Goldberg machine. Recall that a Rube Goldberg is a machine that accomplishes a simple task in a fantastically complicated way.

There are several steps in this process of inventing, regardless of the type of machine you want to create. Who knows what the first step in the design is? The first step in designing a proper solution is to define the need and the audience. You will need to work with your team to decide on what you will be designing. What is the problem you are trying to solve, and who are you designing it for?

Next, an engineer thinks about information that might help to solve the problem. Needed information might include the constraints or limitations on the problem, such as materials or time or safety. For this project, we have some materials already available and we want to use at least three simple machines. We definitely have limited time to our class period, and we want to make sure our contraption is safe.

After all of these things have been decided, engineers brainstorm design ideas. With your team, you will come up with a bunch of different simple machines that could be used to accomplish your final task. Then your engineering team will choose which ones to use and create a plan or drawing of the design.

Why is it important to design your machine first, either as a drawing or a clear idea in your mind? (Answer: To just start building could lead you to a machine you don't like, and we don't want to waste materials.)

Make sure your machine has many different steps and motions in order to complete the end function and look like a Rube Goldberg. Professional engineers draw their inventions before the thing will be built, so we will do that too. Remember to include a materials list.

Once you have a drawing and materials list, and the design has been approved by the teacher, the building can begin. Remember that good engineers try not to use more material than necessary and are interested in an attractive product that works as designed. After everyone is finished, we will rotate through and see all the machines in action.

Engineering Team Members (no more than 4 per group):

Roles: / Team Member
Design Leader: Facilitates brainstorming session and draft plans/drawing.
Time Keeper: Makes sure the group stays on track for each section.
Materials Leader: writes list of all materials needed and keeps track of who is bringing in extra materials from home and what they are bringing; responsible for making sure each member knows what they are bringing.
Execution Leader: Responsible for making sure that the group follows draft plans as well as for making sure no materials are wasted and that the group is following the Task Guidelines.

Team Name: ______

Task: To roll a marble into a cup from a distance (if you want to come up with your own idea, that is great, just please get it approved first!)

Extension (more challenging ideas):

You may do something more complex if you would like the extra challenge!!! Here are some ideas, but you can come up with your own (please get my approval first). You may have to bring in supplies from home if they are not available in the classroom.

·  Turning on the light in the classroom

·  Sharpening a pencil

·  Cutting paper in half

·  Opening the blinds

·  Turning on the ac

·  Opening the refrigerator

·  Turning on a lamp

·  Turning on a computer

·  Printing something

Task Guidelines:

Your task is to design a Rube Goldberg that uses at least 3 different types of simple machines. You may use as many of each as needed (for example, you may use 3 levers, 2 pulleys and 1 inclined plane).

Materials:

There will be a wide variety of random materials available to you (anything other materials you think of need to be approved by the teacher first; for example, dominoes, an egg, a wooden dowel, wheels, etc.):

Some materials available to you may include:

·  Tape

·  Construction paper

·  Marbles

·  Dixie cups

·  Paper towel tubes

·  String

·  Rubber Bands

·  PVC pipe

·  Matchbox cars

·  Kinex

Part I: The Design

1.  Brainstorm with your group about how you want to design your machine (the Rube Goldberg cartoon machines would probably never work in the real world, so you should not design something that closely resembles his cartoon, because you probably would not be able to build it)

Time: 20 minutes

2.  Teacher Approval: Yes______No______

Alterations:______

3.  Draw your design (only necessary for one person in the group to draw it- attach drawing to this sheet when turning in)

Time: 20 minutes

4.  Gather materials

Time: 15 minutes

Materials List: ______

______

Part II: The Build

1.  Review your design and be sure you have all necessary materials.

2.  Build design (45-60 minutes)

3.  Test your machine

4.  Be prepared to share the design and build of your machine with the class. You will perform your task with your machine for the class to see.

Part III: Post-Activity Analysis

1.  Explain how you would find the Mechanical Advantage of your Rube Goldberg Machine.

When Rube Goldberg showed his “Self-Operating Napkin” machine to his friend, he said it would not work. Prove to Rube Goldberg’s friend that the invention will actually work by using the information given and what you know about mechanical advantage and work.

Remember the following equations:

Work = Force x Distance

Mechanical Advantage = Distance from fulcrum to applied force

of a Lever Distance from fulcrum to weight lifted

Math Analysis Questions:

A.  You raise your spoon of soup 0.15 meters with 2 Newtons of force. How much work did you do?

B.  The spoon pulls a string as you move it. How much work is transferred?

C.  The string jerks the ladle, which is a lever. The string is attached 10 cm from the fulcrum and the force is applied 0.5 m from the fulcrum. What is the mechanical advantage?

D.  The spoon throws a cracker past a parrot. (E) The Parrot jumps after the cracker, applying force to the perch he is sitting on. (F) The perch spins around throwing the seeds into a pail. The perch is another lever. It has a mechanical advantage of 2. If it would take 0.5 J of work to move the seeds 0.1 m without the lever, how much force will be needed with the lever?

E.  The extra weight in pail pulls a cord, which goes around a pulley and opens and lights an automatic cigar lighter. If the pail can apply 3 N of force to the cord, and the pulley system has a mechanical advantage of 2, how much total force can be applied to the match?

F.  The match sets off the rocket, which causes a sickle to cut the string, allowing a pendulum with attached napkin to swing back and forth thereby wiping off your chin. If 3 N of force is needed to strike the match, will the system work? ______