9-25-08

Today, we started the class off with a graded daily question:

Each bone in the chain of bones forming your spine is separated by disks of elastic tissue. - given this background, the students were asked the following questions-

**A) What happens when you jump heavily onto your feet from an elevated position? B) Can you think of a reason why you are a litle taller in the morning than the night before**?

- the class provided the following answers-
 * A) Because the disks in your spinal cord have a significant mass, they are said to have inertia, being the desire an object has to remain stationary or at a constant speed, causes the bones to want to keep moving downwards after the jump. If the bones continue to move downward, they are pushed into the tissues that separate them and are stopped by a certain force.**

After the daily question was discussed, the class moved on to complete the activity started yesterday involving a car of weights, rubberbands, and metersticks. The activity was to discover something about increasing force, constant force, and no force at all when each are applied. The conclusions from each are as follows - **- In order for an object to move, it needs to break its inertia, or stationary position. In order to change inertia, a force has to be applied, therefore, providing 0 Newtons of force will cause no change in the object's movement and the object will then remain at rest.**
 * B) When someone is in bed, gravity has no effect on the spinal cord's bones moving vertically. When a person is awake, their spinal cords ar effected vertically by walking, the downward push is given, and gravity pulls the bones down. Because the bones are not being pulled down into the disks of tissue, they remain where they are and a person appears taller than they did before.**
 * - Increasing force increases the speed of an object. The more force applied to an object, the faster it will move. Example- an object with 1 Newton of force applied to it will move half as slow as an object with 2 Newtons of force applied to it.**
 * - Constant force is constant speed. If an object is given a constant force, the object will result in constant speed. Example- If an object moves 1 meter in 1 minute when applied 1 Newton of force, the next minute of travel will accomplish the same distance if the force is remaining constant at 1 Newton.**

The class ended with a worksheet about friction and a pulling force and how they effect one another. One conclusion made was as such -

The bell rang as the worksheet was being discussed and will probably be reviewed tomorrow.
 * - An object in motion will always have, if not equal, then a greater amount of pulling force than friction.**

** Reminders- Test and reading guide are due next Wednesday, October 1st.

Grades We Recieved Back - Unit One Reading Guide, and the Lab from the end of Unit One. **