Complicating Motion

Honors Physics took yesterday to introduce themselves to circular or rotational motion. We examined how to define displacement (as the portion of the circle swept out during the position change measured in radians) and used that displacement to set up for angular speed and acceleration. Today, we conducted a lab investigation where the cause of circular motion (centripetal force) was investigated. Students measured the tangential speed of a mass as it moved in circular motion with a given centripetal force and rotational radius. We varied the radius as one aspect of the experiment and the centripetal force (for constant radius) as a second aspect. We'll finish this lab up on Monday before looking for fully at angular kinematics.

Intro Physics took time yesterday to review their lab work for the Cart on the Ramp investigation, then turned attention to reviewing their Chapter 1 exams. We then jumped slightly into motion by discussing the importance of a frame of refrence when evaluating motion. Today, we picked up with specific descriptors of motion (distance/displacement; speed/velocity) and examined them from a conceptual and graphical standpoint. At the end of class students began to work on a series of practice problems for displacement and velocity and we will go over those on Monday. Remember your basic techniques for working with fractions and your algebra. When something is equal to a fraction, (v = Δx/t), cross multiply, then isolate the desired variable and solve.

Physics D reviewed the graphical method of working with vectors which was the focus of yesterday's work, then took on using the Pythagorean Theorem and the tangent function to streamline the analysis of perpendicular vectors. We discussed vector addition using these techniques and worked a few practice problems in class. On Tuesday, we'll look at vector resolution, which is breaking down a resultant into its x- and y-components and on Monday, we look at the 2-dimensional motion of a cart ascending and descending a ramp. Physics F began their introduction to vectors today, after reviewing their Cart on a Ramp lab that they worked on yesterday. We looked at the motion of our cart and compared/contrasted it with the motion of the ball tossed into the air that played a role in our previous lab investigation. The vector techniques we learn in this first part of Chapter 2 will allow for a deeper analysis of that type of situation, so we'll make sure to spend time learning how to combine and resolve vectors before we move on.