Pulleys and beyond

Here's a recap of what we have learned about pulleys so far. There are two types of pulleys, Single and Compound. There are two types of single pulleys, Fixed & Movable; Fixed pulleys only give you a directional advantage. The force you must use to lift the load is the SAME as the weight of the load. Only one rope supports the load A fixed pulley changes the direction of the lift. Instead of lifting the object up, you are pulling down(much easier) on the rope and lifting the load. The other, a movable pulley, gives you a mechanical advantage and allows you to use less effort to lift the load because the weight of the load is shared by two ropes. The Compound pulleys we covered were  single fixed/ single movable effort down and Single fixed single movable effort up. SF/SM EFFORT UP  used the least effort because it had 3 ropes supporting the load. Two ropes equal half the effort. Three ropes equals 1/3 the effort and so on.

The Rube Goldberg Olympics were officially started. Students are in the process of forming groups. If you do not have a group, see me and we will tale care of that. Each group must sign up on the sheet for their class(bulletin board in back of room). Each group must make a machine that completes a simple task. They must draw a Blueprint/diagram of their machine that shows how it is supposed to work. They will have to write a procedure that describes how their machine works. Presentations will be made in the auditorium to your classmates. Parents will be invited to attend.

That's all for now, Any questions just email me.

Hall of Science Reflection

Hi All,

Here's the assignment, due on Monday.

I'd like a full page reflection on the trip to the Hall of Science. What two things were your favorite exhibits. What attracted you to them. What did you learn. Describe the exhibits as if you were recommending them to your friend. It should include an opening paragraph that introduces the two exhibits, A paragraph about each of the two exhibits you saw and a closing paragraph that ties everything together.  I'm glad you all enjoyed the trip. I look forward to reading your reflections. Keep a copy so it can be uploaded to your E-Portfolio.

The Power to Change.

Today we learned that objects can be classified differently based on how they are used. We looked at a clothespin and saw that when we pinch it open , it is a class 1 lever. The effort is where we pinch it, the fulcrum is the spring in the middle, and the load was the clothespin. When it holds something, like a piece of paper, it is a class 3 lever. Now, the fulcrum is on the end, the effort(the metal bar across the top) is in the middle and the load is the paper. We also made statements about what we've learned so far about levers. Our data tells us that the closer the load is to the fulcrum, the less effort needed to lift it. Tomorrow we will watch an episode of Wired Science.

Breaking News..........

Due to the upcoming walking trip to the Library ( you can all thank Mrs. Bernhardt ), the practical assessment on Lever experiments A & B has been postponed until next week. Friday is the Library trip, Tuesday we will be making the PSAT Survival kits.

FLE123

Today we learned that levers come in different classes. It all depends on what's in the middle of the lever. A Class 1 lever has the FULCRUM somewhere between the load & effort. A Class 2 lever has the LOAD between the effort & fulcrum. A Class 3 lever has the EFFORT between the load & the fulcrum. The way to remember this FLE123. As long as you know what is in the middle, you know what class lever it is. Remember in the middle ONLY means that it is somewhere between the other two lever parts. We also learned that a Convention is a generally accepted symbol. For our experiments, a triangle is the fulcrum, a square is the load, and a circle is the effort. Tomorrow we will try to set up the different lever classes.

Quiz alert:  You will be given a practical exam this week. You will be asked to use your lever and figure out the effort needed to lift the load. You will be asked to graph your results.