9-26-08

Annie Feingold Friday September 26, 2008

The bell rang and everyone returned to their seats. The topic for today is friction and pulling forces. To start off the class Mr. Manning instructs the class to answer the Daily Question: Pertaining to question number two, Mr. Manning tries to explain by stating, "Unbalances objects always cause forces to accelerate". This means that because Team Aristotal had more force on its side, it caused Team Galileo to accelerate therefore losing the game of tug-of-war. __**Reminder About Test**__ Mr. Manning then goes on to remind the class that we will have a test on this chapter on Wednesday September 31st and the reading guide packet is due on the same day. The class was then instructed to finish the two questions at the bottom of the Unbalanced Forces Worksheet. This worksheet introduced another type of force called friction. //Friction// is a resistance force that act in the direction that is opposite to the direction of the motion of an object. If the amount of pulling force applied to a cart is equal to the amount of friction force, the cart will not accelerate, it will stay still. On the other hand of the amount of pulling force is greater than the amount of friction force, the cart will accelerate. The questions and answers to this worksheet are as follows: If the pulling force and friction force are equal, the cart moves slowly and at a constant speed. 2. **Can the friction force ever be larger than the pulling force?** Yes, when pushing force is only for a second, the friction will soon overcome pushing force and it will decrease in acceleration and stop. The next activity was a very interesting one. We got to hear Mr. Manning rap, and might I add it was quite the sight to see. The rap he had created was intended to give us an example of how these forces play a role in everyday life. He did this by giving us a detailed rap about him driving in his Tracer. The final activity for the day, Mr. Manning had us make predictions on the lab we would be participating in on Monday, but before we started on our predictions, he had us record a few definitions:
 * __Daily Question__**
 * 1) **What is the £F?** 10 N
 * 2) **Are the forces balance on the rope?** No
 * 3) **Who wins?** Team Aristotal
 * __Unbalanced Forces Notepage__**
 * 1) **How are the two forces related if the cart is moving at a constant velocity?**
 * __Autocontrol__**
 * __Lab__**

To add on to these definitions and make more sense of it, Mr. Manning asks the class "If somthing is dynamic equilibrium, how will it move?"-- The answer is in a straight line. This was going to be very useful in the experiments.
 * Static- Unchanged, no motion
 * //Equilibrium//- Balances, equal
 * //Dynamic-// Change, motion
 * 1) **If a weight of about 10 N from the ceiling using spring scales, what will be the readings on each spring scale in each case?** My predictions were, a) 7/5 N b) 5/5 N c) 3.5/3.5/3.5 N d) 6/4/2 N
 * 2) **Starting with configuration B from question 1, how will moving the hanging weight to the right or left affect the reasings on the 3 scales. Explain what will be different and what will remain the same.** I predicted a difference would be that the measurments on the scaled would flip and a similarity would the that it will be the same two measurments just on the opposite scales.
 * 3) **What would happen to the scale readings as Burl, the painter, walks along his scaffolding?** The scales will simply trade readings as Burl walks to the other end.

The bell finally brings after and exciting period of learning and the students all gather thier belongings and race out of the classroom.