Motion and More Motion

Introductory Physics is the only class not currently working through motion, but they'll be there on Friday. This crew reviewed their graphing homework before taking on the concepts of scientific notation and significant figures. As we practiced in class, you should be able to quickly and efficiently work with scientific notation on your calculator and correctly use significant figures for answers to calculations or for reporting data. You'll get plenty of practice with this tomorrow and we''ll go over this practice and all of Chapter 1 as part of our review on Wednesday. Thursday's exam will end our introductory unit, then we'll march in to Physics proper with a look at one-dimensional motion.

Honors Physics took their ideas about one-dimensional motion and looked at the special case of vertical motion and free fall. If gravity is the only force accelerating an object (no air resistance, friction, thrusters, wings or parachutes), the motion is termed "free fall," and we know two things about the motion - the acceleration is constant and the acceleration is the value for acceleration due to gravity (accepted average = -9.81 m/s²). The negative sign for g indicates the direction, which is always downwards towards the Earth. Beyond that, every concept and formula you worked with for horizontal motion fully applies. Make sure you understand the relationship between signs for velocity and acceleration, in terms of how they affect motion, and how to work problems when motion is along the y-axis. You'll get practice with this tonight and more tomorrow in class. Big things to remember: you know the value for acceleration in free-fall, pay close attention to signs and motion can have several components such as a rocket that is launched with thrusters that turn off at some point. Keep those thinking caps on!

Physics A and B started their work on motion today with a look at how motion is defined and the importance of a frame of reference for that definition. We looked at many examples of how changing the frame of reference changed how a single instance of motion was described. We took time to disentangle distance/displacement (two ways to describe the magnitude of the motion) and speed/velocity (two ways to describe the rate of the motion). This will become more clear when we tackle vector vs. scalar quantities and you'll get a better understanding of why we tend to use displacement/velocity far more often in Physics than distance/speed. Our feet were just getting wet in the area of graphing motion before the bell, so that's where we'll pick up next.