As a Media Center Assistant, my primary focus for the first half of the school year is to work with students in grades 5-8 on their Science Fair project. Science Fair rules dictate that no more than 3 students in grades 5 & 6 and no more than 2 students in grades 7 & 8 may work on a project together. This rule makes it necessary to provide a variety of resources in support of their varied interest and the different directions they may choose to take with the same project. Flexibility (within reason) with his/her investigations is necessary for the student to have an input and a greater interest in their project.
The focus of this unit is on small group instruction and contains a variety of resources where a student can research background information for his/her topic. This background material will provide the student an opportunity to look at his/her project in a variety of ways and help them decide on the focus of their project.
In most cases, the student involvement with physical science has been very limited. This lack of background is a reason why we will rely on computer animated programs and hopefully find a mentor qualified to help them in their area of interest.
The computer activities will allow the student to work at home and/or in school to introduce and reinforce the scientific principles that will enable them to better understand the necessary information about the subject and complete a meaningful project.
Before we begin discussing simple machines and engines, we should have an understanding of work and energy. The definition of work is “exerting a force through a distance.” After giving them six to ten examples of work being done or not being done with several different systems, have them use the equation W= F X D to answer some questions. Questions and examples can be found in most Physical Science textbooks.
Once you are satisfied that the student can distinguish work from exerting a force, begin a discussion on energy. Energy is the ability to do work. The Brainpop website:
http://www.brainpop.com is a good starting point. It has short movies and a quiz about several different forms of energy. The quiz gives the student immediate feedback to determine his/her understanding of the topic.
The available topics are Energy Sources, Forms of Energy, Heat, Kinetic Energy, Potential Energy and Nuclear Energy. You may look at two movies/day without having to pay for this service.
Before we leave this introductory section about energy, we should stress the differences between renewable and nonrenewable sources of energy. This will give them a better understanding why certain sources of energy production are being studied more aggressively than others for future uses. A good website is: http://www.eia.doe.gov/kids/whatsenergy.htm. With this website, you may have the student just list the different forms of renewable and nonrenewable sources of energy or they may “click” on a form for a more in-depth explanation about each form.
At this time, you may want to distinguish between heat and temperature.
Again there is a movie about temperature and another on heat available at Brainpop. Multiple choice questions are used at the end of the movie. These questions will allow you to evaluate their basic understanding of the topics.
I have found that allowing them to do an investigation “Heat and State Changes” helps them to distinguish between heat and temperature. In this investigation, the student and/ or teacher heats a beaker of ice until it boils. A data table (temperature vs. time) will be used to construct a graph when all the data are collected and recorded. The time scale you use will depend upon your heat source. Constructing a graph from the data helps them to visualize what happens when you discuss what is happening during the change of state.
If students have trouble with the concept of molecular motion during the changes of state, I have found using the example of students in a classroom helps clarify this concept.
Solid - Definite shape, definite space.
Analogy:
The students are in the classroom all sitting at their assigned seats.
As the period goes on, they begin to get “antsy” in their seats.
Liquid - No definite shape, definite space.
Analogy:
The students begin to move around the room but do not leave the room.
Gas - No definite shape, No definite space.
Analogy:
Finally the bell rings and the students leave the classroom going out different doors and proceeding to different classrooms.
Another activity that sometimes helps them to understand molecular expansion is to cover a beaker with a balloon. Explain to the student that you are creating a closed system with this set-up. In a closed system, no mass gets in or out of the system. Mass the balloon and beaker. Heat the air in the beaker and watch the balloon expand. Mass the balloon and beaker again. There will be no noticeable difference in mass. They will observe that it in this closed system, with no air getting in or out of the system and the mass remaining fairly constant, the only logical explanation at this point is that the molecules are moving faster and further apart.
To show how the construction industry uses the principle that most materials expand when heated and contract when cooled, ask the student why there are expansion joints between spans in a bridge or in the walls of some large buildings. Hopefully, they will remember that most materials expand when heated and contract when cooled.
As this unit will deal with engines & work, we should touch on horsepower. James Watt is credited with inventing this term by working with ponies lifting coal at a coal mine. Go to the website http://auto.howstuffworks.com/horsepower1.htm to get this information. This site explains how a dynamometer is used to determine the horsepower of an engine. The chart below how horsepower impacts the price of an automobile.
This chart is found at the same site and would be of interest to most students.
Horsepower Weight (lbs) Power:Weight 0-60 mph (seconds) Price
Dodge Viper 450 3,320 0.136 4.1 $66,000
Ferrari 355 F1 375 2,975 0.126 4.6 $134,000
Shelby Series 1 320 2,650 0.121 4.4 $108,000
Lotus Esprit V8 350 3,045 0.115 4.4 $83,000
Chevrolet Corvette 345 3,245 0.106 4.8 $42,000
Porsche Carrera 300 2,900 0.103 5.0 $70,000
Mitsubishi 3000GT bi-turbo 320 3,740 0.086 5.8 $45,000
Ford Escort 110 2,470 0.045 10.9 $12,000
How far you go with the study of horsepower will depend on the age of the student and purpose of his/her project.
