PHYSICS 161

There is a homework assignment due (almost) every class period!
If on paper, they should be turned in at the alphabetically-labeled box at the front of the classroom, before class begins!
If on WebAssign, they are due at 1 A.M. of the night in question.
So a WebAssign(ment) due on, say, Friday, is due no later than 1 hour after Midnight on that Friday, i.e., at 1 A.M. Saturday morning.

No. XXXVI: due on viernes, 22 de noviembre

1. There are no paper problems due today.
2. There are 2 questions and 2 problems on WebAssign, due tonight, all from Chapter 32.

Solutions to HW 36 may be accessed after they are due, by clicking right here.

No. XXXVII: due lunes, 25 de noviembre

1. There is one paper problems due today:
   A magnetic compass has a needle aligned with the horizontal component of the Earth's magnetic field, at a place where that component has the value of 16 µTeslas. The needle has a total mass of 50 grams and a total length of 4.0 cm. It is balanced at its center of mass, in the middle, and we will assume that it rotates quite freely, with only negligible friction.
   After the compass is given a momentary gentle shake the needle oscillates with angular frequency = .045 radians/second. Treat the needle as a uniform, long thin rod mounted at its center, which oscillates converting magnetic potential energy into kinetic energy and back again.
   1. Use this notion and the above data to determine its total magnetic dipole moment.
   2. Then model the needle further as a cylinder, of cross-sectional area 0.4 mm², and calculate the magnetization, M.
   3. Now take the density of iron as 7900 kg/m³ and the molar mass of iron as 55.847 g/mole [as given in your text in Sample Problem 32-2] and determine the average magnetic dipole moment of the individual atoms in the needle.
   4. Lastly, take the number, given in that Sample Problem, for the actual magnetic dipole moment of an individual iron atom, namely µ_Fe = 2.1 x 10^-23 J/T, to estimate how many of the iron atoms in this needle are cooperating in its magnetic effects.
2. There are 3 problems, concerning induced magnetic fields, and 1 question, from Chapter 33, on WebAssign, due tonight.

Complete solutions to HW 37 may be accessed by clicking right here.

No. XXXVIII: due miercoles, 27 de noviembre

1. There are no paper problems due today.
2. There are 1 question and 2 problems on WebAssign, due tonight, all from Chapter 33, concerning LC circuits and their oscillations.

Complete solutions to HW 38 may be accessed by clicking right here.

The problem is due on the last day of class, i.e., on 6 December.
After that time its solution will be found at this linked webpage.

No. XXXIX: due lunes, 2 de diciembre

1. There are no paper problems due today.
2. There are 3 problems on WebAssign, due tonight, all from Chapter 33, concerning oscillating electric circuits.

Complete solutions to HW 39 may be accessed, after they are due, by clicking right here.

No. XL: due miercoles, 4 de diciembre,

1. There is one paper problem due today: Chapter 33, Problem 41P.
2. There are 3 problems on WebAssign, due tonight, all from Chapter 33, concerning oscillating RLC circuits, and power extraction from and input to them.

Complete solutions to HW 40 may be accessed, after they are due, by clicking right here.

No. XLI: due viernes, 6 de diciembre,

1. on Webassign for Saturday night, i.e., very early Sunday morning at 1 AM, there are 1 question and 3 problems due.

Complete solutions to HW 41 may be accessed, after they are due, by clicking right here.

The FINAL EXAM will be on Wednesday, 11 December, from 10-12 AM.

Coverage will be Chapters 22-33 or (some of) 34, with some emphasis on Chs. 31 - 33 or (some of) 34.

Solutions may be accessed here.

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Last updated/modified: 12 December, 2002