Thursday's class - Caroline Hufford

On Thursday, we did the speeding up and slowing down lab with the whole class and Mr. Burk. Before we did the lab, though, Mr. Burk asked us how you knew if you were moving towards or away from the origin. After drawing a graph, we saw that if position and velocity have opposite signs, then you are moving towards the origin. We then did the lab. There were lots of different examples of what would happen if you changed the position of the car and of the motion sensor. What it came down to was that if velocity and acceleration have opposite signs, that means the object is slowing down. If velocity and acceleration have the same signs, the object is speeding up. On Thursday we also learned how to find the displacement of an object whose position doesn't start at 0 m. The position of the object equals the initial position plus the initial velocity times time plus half acceleration times time, squared. Or, (change in)

x = xo + Vot + 1/2at^2. This is the model for the position at any time of an object with constant acceleration. If you have a constant velocity however, x = xo + Vot.