Let the Sunshine In!

Honors Physics spent the first part of the period going over their Chapter 8 exams. Although many people did well, some had a hard time with the material. Make sure to get with me to schedule a retest for next week and to come to me for any help you need with the concepts or problems. We then continued on with the topic of fluid pressure and how it varies with depth. Regardless of the fluid, as me move deeper in to the column, pressure is going to rise. The degree of rise depends on two things – the depth of descent and the identity of the fluid. The same goes for ascending in a fluid column, the pressure decreases based on magnitude of ascent and identity of fluid. Tomorrow’s lab will allow you to investigate this relationship with a column of water and examine the predictability of the relationship.

Physical Science B undertook an investigation for heat conduction/insulation. Heat is better retained in a bottle covered by a dry cotton or dry wool covered socks that if left uncovered. When you wet the cotton, however, the ability of the fabric to retain heat is severely diminished. Mom is right when she yells at you to get out of your wet clothes. The rate of heat loss in wet clothing can be very dangerous to humans, based on the surrounding air temperature. Dry clothes are a valuable piece of survival gear! Not all materials are as poor as cotton for retaining heat while wet. Wool retains heat quite well when wet, so despite being soggy, they are a better bet for hunters and sportsmen when they are out and about. The wait time for the investigation was spent working on MCAS review questions for work, energy, momentum and forces Make sure to finish up the MCAS review multiple-choice questions by tomorrow so that we can go over them in class.

Physical Science E went over their Chapter 12 exam and then moved into a discussion of heat and temperature. The concepts were defined and contrasted and then time was taken to examine the commonly-used temperature scales and how thermometers and thermostats function. We then began a discussion of heat transfer, using the lab as a springboard for the topic. Tomorrow, we will continue with this discussion, comparing and contrasting the methods of heat transfer.

Physics F and G began a discussion of forces in fluids. We put a specific definition to fluids and contrasted liquids and gases. We then turned attention to the concept of buoyant force and the role it plays in objects floating or sinking in a fluid. Density, despite what most people think, is not the player that makes things float or sink. Net force is what is responsible for the acceleration of an object, so it is the net force acting on an object in a fluid that determines whether it floats or sinks, the rate of descent and the depth to which something will float/sink in a fluid. Tomorrow, we will turn attention to fluid pressure and G Block will conduct a lab that focuses on how fluid pressure varies with depth.

Homework

Honors Physics A: Read over lab sheet
Physical Science B: Complete MCAS practice multiple choice items; have lab write up for Friday
Physical Science E: None
Physics F and G: Practice 9B #1, 2; Practice 9C #1 and the 9.2 Section Review #3, 4