Winding Down the Week

Honors Physics reviewed the process of using Newton’s 2nd Law of Motion to solve for an object’s acceleration. Remember that an acceleration given in a problem is a product of the net force and before you can calculate acceleration, you must first find the net force acting on the object. This is where free-body diagrams come in handy – they give you a way to visualize a problem and determine where forces are acting. With an incline, remember to break down an object’s weight into components and watch for objects being pushed or pulled at an angle while on an incline. Today, we discussed the nature of frictional resistance and the basic meaning of coefficients of friction. You should be use coefficients of friction to calculate the static or kinetic friction acting on an object and the object’s resultant acceleration.

Physical Science B further discussed gravity and its connection to weight. Towards the end of the period, we took time to discuss and demonstrate “apparent weightlessness” and explore the concept of orbital motion. On Tuesday, you will conduct a lab to examine Newton’s 2nd Law of Motion in more detail before we start projectile motion on Wednesday.

Physical Science E took the class period to review their universal gravitation problems. Folks are having difficulties with calculators, especially with the use of scientific notation. To determine how best to work with scientific notation on your calculator, give yourself a simple problem (one for which you know the answer) and work it until you find the correct keystroke order to work the problem. The worksheet answers are still online – the link can be found 2 posts ago – see if you can remedy your difficulties somewhat over the weekend and we will address the problems again when you return on Tuesday.

Physics F discussed Newton’s 2nd and 3rd Laws of Motion. Remember that when we discuss Newton’s laws of motion, they exist irrespective of the force involved in the problem. The action of both field and contact forces are described by the laws of motion, so they will apply to any problems that you are asked to solve. Physics G explored the concepts of weight and the normal force and began a discussion of the nature of friction. Think back to your lab investigation as we move through friction and consider how your observations during the experiment are explained by the theory.

Homework

Physics A: 4D and Chapter Review # 39, 53 and 68 for Wednesday
Physics B: None
Physics E: Reexamine your gravity problems and look for sources of error. Practice your calculator skills
Physics F: None
Physics G: 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.

HAVE A GREAT LONG WEEKEND!