9-25

=The Physics Journal= By Liz Chever For today's class on **September 25, 2008**, we learned a lot about speeds and forces through activities and notes. The agenda for the day was the graded daily question, to finish the "Strenchin' for an Answer" Lab, discuss and take notes on the worksheet "Unbalanced Forces", and lastly we took a survey on the computer for Classrooms of the Future. There were no assignments to hand in for the day, but we did recieve **page 14, the "Unbalanced Forces" worksheet**. The **graded daily question** was stated as: Each bone in your spine has elastic tissue. What happens when you jump heavily onto your feet from an elevated position? The answer to this question is that the spine is at rest, and inertia causes the tissues to resist that acceleration. The second question was why are you taller in the morning than the night before? The answer to this is that the tissues are stretching in the morning when you get up instead of the night before, when they are at rest. When we were finishing the lab on **"Stretchin' for an Answer"**, we found that when you are going zero or close to zero, the cart moves at a constant speed. When you're pulling at a constant speed, the cart also moves at a constant speed. Lastly, when you're pulling at an increasing speed, the cart increases in speed. For the **"Unbalanced Forces" worksheet**, there is no acceleration if the amount of pulling force equals the amount of friction force. There is acceleration if the amount of pulling force is greater than the amount of friction force. If an unbalanced force is applied to an object, the object will accelerate. In conclustion, there is a Unit 2 test and reading guide that is due next **Wednesday, October 1, 2008.**

This picture is an example of how when you're forcing increasing speed, the car increases as well.