How's About that Thursday

Honors Physics went over their lab investigations and electricity exams before diving deeper into electromagnetism. Students discussed the effects of coiling a wire on the strength and character of the magnetic field and contrasted air-core solenoids with iron-core solenoids (electromagnets). The magnetic field profile of a solenoid was discussed and likened to that of a bar magnet. Tomorrow, we tackle magnetic forces.

Physical Science B and E reviewed the electricity open-response MCAS items and discussed strategies for maximizing scores on these questions. Students were then given class time to work on corrections for their electricity exams. Students can receive 1/4 of the points they missed added back to their exams if they explain why they chose the incorrect response and the reasons the correct choice is correct. Books, notes, peers, parents and I are all resources for the corrections. If you have any items that you cannot work through, see me tomorrow before school or at the start of class.

Physics F began to discuss magnetism and spent time in class describing magnetic fields. We examined the pattern of field lines associated with bar magnets and contrasted with the pattern we see for Earth’s magnetic field. The use of a compass for navigation was discussed, and the magnetic properties of a lodestone was demonstrated. Tomorrow, a lab that allows students to investigate different types of permanent magnets and study the effect of winding number of the strength of an electromagnet.

Physics G conducted their magnetism lab today which targeted both permanent and electromagnets. Students found that magnetic field strength was correlated with distance from the magnet and that when evaluating the field along the length of the bar magnet, the field showed an obvious switch from one sign or pole to the other. Different types and shapes of magnets also act as dipoles, but field strength is not always a simple factor of size or shape. For the electromagnet, the number of windings had a linear relationship with field strength – more windings, stronger field – and a sharply struck nail loses a great deal of its magnetic field strength. Now, look ahead to magnetic domains and figure out why that’s the case.

Homework

Honors Physics A: None
Physical Science B and E: Complete test corrections
Physics F: Read lab protocol sheet
Physics G: Complete lab write up