Grace+Carroll+12-11-08

On Thursday, December 11, 2008 I decided to observe Mr. Manning’s fourth period Physics class as Manheim Township High School. The first thing Mr. Manning did was check the student’s homework from the night before. After that, the class reviewed any of the homework problems they had questions about. The next thing the students did was the daily question. The daily question today had to do with motorboats and speed. Motorboats crossed a river pointing in three separate directions (shown in the visual accompanying this article), and each motorboat had the same speed relative to the water, as well as the same water flow. The students had to answer three questions including; which boat took the shortest path to the opposite shore? which boat reached the opposite shore first? and which boat provided the fastest ride? Boat A took the shortest path to the opposite shore, while boat B reached the opposite shore first. Boat C provided the fastest ride because the boat is flowing the current; the speed causes it to flow downward. Along with the daily question, the students continued to learn about subtracting vectors, and received three pages 18b, 19 and 20. When finding the difference of two vectors, you find it the same way as adding vectors, except you add the opposite of the vector you are subtracting. (1-2=1+(-2). Let’s say there are two vectors, Vector A is 100 N West (0degrees) and Vector B is 40 N (340 degrees). The first thing you do is find out what B-A is, and then what A-B is. After you find this out, you have to graph the vectors. After the class completed a few practice problems, they learned about components. If one vector and another vector add up to equal the same amount of degrees, they are components of another vector. The example on the worksheet was that Mr. Physics was swimming across a river, and his resultant speed was 2.5 m/s in a 53 degree direction. Mr. Physics is continuously moving across the river at 2.0 m/s and is being swept downstream at 1.5 m/s. 1.5 m/s at 0 degrees and 2.0 m/s at 90 degrees add up to the result vector, they are components of the 2.5 m/s vector. If two vectors are right angles to each other, they are perpendicular components. Every (perpendicular) vector is broken down in a North, South, East or West component. To measure the length of a perpendicular component, one has to draw the original vector and then draw the component on the North and South axis and East and West axis. It was a very eventful day learning about components and drawing vectors, and hopefully I will be able to come back another day! -Grace Carroll