Teetering on the Brink

Back! Back you foul contagions! Pardon me while I whip out my arsenal and try to fight off the marauding hordes…

Ok...I'm back...but I am doubting my efforts will amount to much...

Honors Physics reviewed their lab and the homework problems assigned a few days ago. Those problems were quite robust in the number of skills required to affect a solution. You have to really draw on your knowledge of forces and motion to approach those problems and , actually, that is the way that real-life situations actually work. With the extra time needed for test preparation, the exam is postponed until at least Monday and we’ll use tomorrow for review. Try reworking problems that gave you difficulty today and see if our discussion helped you sort things out.

Physical Science B completed their discussion of Newton’s 3rd Law of Motion and used that to segue into an examination of momentum. If we were to follow Newton’s lines of thought, we would have examined momentum first, but doing it now is not a problem. Momentum actually helps people understand Newton’s laws a little better and adds a dimension of analysis for our study of motion. Physical Science E had this discussion yesterday and added more study of the concept of impulse today. Impulse is a pretty common-sense topic – an object’s change of momentum depends on the size of the applied force and the length of time that force is applied. We can also turn around our thinking to consider that the size of the force depends on how much momentum change was produced and how quickly it occurred. Both perspectives have many daily-life applications, and it is nice to be able to use one formula to attack a wide variety of problem types.

Physics F discussed air resistance and how it affects the motion of falling objects. For falling objects, terminal velocity can come into play if the object has sufficient time to fall, and air resistance offers the explanation for why heavier objects fall to the ground faster than lighter objects. Your lab tomorrow will allow you investigate air resistance for two objects that differ profoundly in mass.
Physics G conducted a lab centered around air resistance and found, unsurprisingly, that the velocity of a falling textbook was greater than the velocity of a falling coffee filter. Further, increasing numbers of stacked coffee filters fell with increasing velocity. A single coffee filter hit terminal velocity pretty quickly; the book didn’t have time to reach it at all. Five coffee filters took longer to hit terminal velocity than did fewer coffee filters. All those results would be predicted by our discussion of air resistance’s effects and you should be able to craft a nice discussion section for your lab synopsis based on this knowledge.

Homework

Honors Physics: Rework homework problems, if necessary.
Physical Science B and E: None
Physics F: Read lab sheet. Complete p. 153 #32-36 for Monday.
Physics G: Complete lab write up