Wild Wednesday

Honors Physics spent the period kicking wooden blocks around on the floor to investigate kinetic friction. Actually, that was only a piece of the investigation, but it was the most entertaining to watch. Static and kinetic friction were both targeted in today's work. Static friction outclasses kinetic friction in terms of magnitude (given the same surfaces). You graphs demonstrated the force required to start the wood block moving was greater than the force required to keep the block moving at constant velocity. The peak force on your graph was indicative of the value for F_s,max, which must be overcome by an applied force for a object to be set in motion. Your value for F_k could be inferred from the graph segment indicating the block moving at constant velocity. Constant velocity indicates F_net = 0, so the applied force is being matched by the force of kinetic friction. Adding mass to your system increased the force of friction by increasing the normal force the block experienced. Part 3 of your investigation allowed you to look at position-time and velocity-time graphs for motion where kinetic friction acted as the net force. The acceleration value from the velocity-time graph (which was a constant value) and the block's mass allowed you to calculate the magnitude of the frictional force using N-2. We' start discussion everyday forces like friction and weight tomorrow. The lab isn't due until Friday, but we'll address any questions about the investigation tomorrow.

Physics B reviewed their Air Resistance lab and used the lab to illustrate various topics discussed in the chapter. We took some extra time to go back over Newton's 3^rd Law of Motion and students had some class time to begin working on their N-3 critical thinking questions. We'll go over these tomorrow before reviewing for Friday's exam.

Physics E shared answers for their N-3 critical thinking questions, then began the review process for Friday's exam. We went through the note packet, highlighting key topics and students are strongly encouraged to take some time tonight to go through the exam material and come with questions tomorrow to address in class.

Physical Science reviewed Newton's 1^st Law of Motion and then tackled Newton's 2^nd Law. Although many people view N-2 only as a formula F = ma or a = F/m, be very aware that N-2 actually says about the interaction of F_net and inertia to determine an object's change in motion. We took time to work a couple of practice problems with the N-2 formula before beginning a graphing assignment for Newton's 2^nd Law. Tomorrow, a lab investigation for N-2 is on the agenda.

Homework

Honors Physics: Lab write up due Friday
Physics B: p. 84-85 of the ancillary packet #19, 24, 25, 28, 29, 32, 36, 37
Physics F: Prepare for Friday's exam
Physical Science: Complete #33 on page 370 (due tomorrow) and the 11.1 Section Review (due Friday)