Goodbye, Columbus

A dreary Tuesday after a long weekend – not the most auspicious way to start the week, but we seemed to manage fine…

Honors Physics completed their discussion of friction with an examination of the impact of air resistance on motion. Tomorrow’s lab targets friction, both static and kinetic, and the problems due Thursday will give you a good bit of practice with the quantitative aspect of friction studies.

Physical Science B investigated Newton’s 2nd Law of Motion with an activity that used a constant force to accelerate various masses. As predicted, the larger the mass (inertia), the less the acceleration. Hopefully, for the extension, you realized that with the same mass sets, an increased force would produce an increased acceleration. We will discuss the lab tomorrow and continue on with our examination of projectile motion.

Physical Science E discussed free fall and its relationship to “weightlessness.” Motion in something like the space shuttle is actually only apparently weightless due to the fact that both the shuttle and the astronauts exist in constant free fall. Our discussion then turned towards orbital motion and projectile motion. We will continue on with this tomorrow and include a demonstration of the independence of horizontal and velocity vectors in projectile motion.

Physics F discussed weight and the normal force today, for objects on horizontal surfaces and on inclines. These concepts will lead us into a discussion of frictional forces, which depend on the magnitude of the normal force to which an object is exposed. Physics G continued their discussion of friction and the coefficient of friction. Static friction trumps kinetic friction in magnitude, so it is not surprising that the coefficient of static friction is larger than the corresponding coefficient of kinetic friction for the same two surfaces in contact. In problems, you could be asked to solve for the friction in a system or for the coefficient of friction. First, you will need to calculate the normal force on the object if it is provided, and then complete the problem with that information. Also, pay attention for situations where an object is slowing down. If friction is the only force acting on the object (in the horizontal direction), then you can use the acceleration to calculate the frictional force (m x a).

Homework

Honors Physics: Read lab sheet for tomorrow and complete 4D and ChRev #39, 53, 68 for Thursday
Physical Science B: None
Physical Science E: Complete lab write up
Physics F: p. 153 26-30. Do only items a and c for question 28 and answer question 29 only for items a and c of question 28.
Physics G: 4C #2, 4.4 Section Review #2-6