Friday the 13th!

Gloomy, clammy but no murderers wearing hockey masks. I'll give the day an "E" for effort...

Honors Physics conducted a lab investigation that was a little off our regular protocol. Rather than a detailed lab sheet, the basic technique was described, but the actual details of the apparatus and experimental protocol was left up to the students (especially for testing other variables). Groups had to use a motion detector and force sensor to assess the centripetal force on a pendulum system and relate it to the tangential velocity, pendulum mass and radius. Does F_c = mv_t²/r? After the basic experiment, students had to change the mass, radius and displacement variables and see if they affected the relationship and/or the magnitude of the centripetal force. On Monday, we will discuss the lab and jump headlong into angular motion.

Physical Science B and F endured their forces in fluids test. Scores were on the low side, for both the conceptual questions and the math problems. We will go over the exams next week and work to firm up the information in people’s minds. Also on Monday, we begin our study of work, power and simple machines. Make sure to have the homework problems completed and Physical Science B should have their lab write up prepared.

Physics F and G worked on understanding the nature of the radian and how we use radians to discuss displacement in circular motion. Students conducted a brief activity to see how the value of a radian is determined, using wire and circles drawn with a compass. Sure enough, it takes about six and a quarter lengths of wire, each the length of the radius off a circle, to cover the circle’s circumference. The angle swept out by one of those pieces of wire equals one radian. A full circle equals 2π radians. Work to drill the concept of radians and how to work with them in problems (and on your calculator) into your brain. For the next two chapters, displacement of objects engaged in circular motion will need to be in radians to analyze the motion mathematically.

Homework

Honors Physics A: Complete lab write up
Physical Science B: Complete lab write up. Complete practice problems on page 379 and 381
Physical Science E: Complete practice problems on page 379 and 381
Physics F and G: Physics G should read their lab sheet, Physics F has no homework