Today, we explored balanced and unbalanced forces with an all class tug of war. Our activity sheet is attached below.

Today we discussed the difference between mass and weight. Mass is how much matter is in an object and measured in kilograms. Weight however is force, which means it is mass multiplied by the acceleration due to gravity (on the planet where are currently standing). We solved several more force problems using Newton's second law (F=ma) as well as calculated our weight on different planets (on different planets your mass is the same but your weight will change based on the amount of gravity). 

Newton's second law states that the force on an object is equal to the objects mass multiplied by its acceleration. Or more simply: F=ma. Click Here for some example problems and help solving for force. In class we added newton's second law to our notes, as well as solved several force problems and began our discussion of gravity.

With the completion of our conclusions, we are moving on to a new unit, FORCE. More than just what binds the Star Wars Universe together, a Force is a push or a pull that can cause an object to move. One of the first forces we will examine is friction. A classic experiment that we recreated in class is overlapping the pages of two books together then trying to pull them apart. The MythBusters did a large scale version of this experiment that Mr. Houde also attempted in class.

After three intense days of experimentation and data analysis, we finally wrote the conclusion to our speedy lab. We compared distance vs. time graphs to speed vs. time graphs, and interpreted all our our data to tell a story. The motion unit is now complete. Tomorrow will will begin our new unit: Forces.

           Today we raced! Students ran and race-walked across the gymnasium, while their peers timed them at distances of 20, 40, 60, 80, and 100 feet. 
         Once we had all of our data recorded, we began to analyze it by calculating speed from the distance and time measurements.  
            Tomorrow we will graph and further analyze our data as well as conclude our lab.

We continued our study of acceleration by trying a bunch more practice problems. If you want to watch another version of how to solve acceleration problems, watch this video from Flipping Physics. Something important to learn from the video is that before you can calculate acceleration, all of your units (or dimensions as Mr.P says) must match. If you are solving for acceleration in m/s/s then your velocity must be in m/s and your time must be in seconds.

Mr. Houde took the reins today and helped students learn how to calculate acceleration, as the change in velocity divided by the change in time. One of the more difficult concepts to understand is, why is acceleration measured in meters per seconds squared? Using algebra we were able to show that when dividing velocity (m/s) by time (s) we get: m/s/s or meters per second squared. 

Gold Tape Question:  If you step off a 30m high dive, and you fall (accelerate) for 2.47 seconds, what will your velocity be when you hit the water? (Hint: look up the acceleration of all falling objects on earth first)

In class students took a quiz over motion graphs and calculating speed. At the end of class students helped derive equations to find distance and time and then were introduced to the "speed triangle." Tomorrow we will learn how to calculate acceleration.