week of november 30, 2009!

This week we learned how to make a force diagram. We learned that we could represent an object by a dot, and the forces being exerted on the object by arrows. We also learned that when an object is staying in place, the forces being exerted on it are equal. We learned this because Mr.Finley put Jeremy in the front of the room and had him hold a basketball in one hand and a bowling ball in the other. Even though both balls were sitting still in Jeremy's hands, we learned that the bowling ball was exerting more force on Jeremy's hand because he had to use more force to hold the bowling ball than the basketball.
We also learned that a table and other objects and exert force. We learned this by writing down our answer to a question and having a class discussion. We learned that a table has to push to keep objects on top of it.
This week we also learned about force by pushing Mr.Finley's car. When we pushed it and then let go, it kept moving but at a slowing speed. This happened because the friction on the ground was slowing it down. We also learned that when we pushed it and a few people pulled the opposite way, the car slowed to a stop and then started going in the opposite direction