11-25-08

Tuesday morning, the day before our Thanksgiving vacation, students walked in the classroom looking for an easy learning-free day. The period was pretty easy, but not learning-free. Mr. Manning started with a notebook check. Then the class moved on to the question of the day. The question was: Yesterday, you observed that no matter the type of collision, equal forces were __always__ applied! Why might one vehicle receive more damage? Some answers to the question include inertia, where one car hits the other car, and the material the car is made of.

Next, we took a look at page 3, Mini-Tug-o‘-War. We read the page and then in small groups we tried it for ourselves. Using two spring scales, one person pulled harder than the other one to see the differences in forces. Our conclusions drawn from the activity were that mass and speed have nothing to do with the force. All pulling forces are always equal.

As a class, we took a look at pages four and five that we picked up at the beginning of the period. Page four explains Newton’s 3rd law, the law of action and reaction. The law states that all forces arise from the interaction of particles, and when one particle exerts a force on a second particle there is always and __equal__ and __opposite__ reaction force by the second particle on the first particle. Page five has multiple examples of Newton’s third law. One example is below:



Head bumps ball. Ball bumps head.