Week 3

You are working on Ch. 3 HW for Wed. Jan. 21---we have covered material. Ask questions/Teams, in office, etc.

Ch. 3        9,13, 16, 20, 23, + your cyop prob. Due Wed. Jan. 21

ch. 4       6,7,9, 16, 18, 32, 36, plus your problem --- (last time I am reminding of CYOP---it is on every HW) Due Wed. Jan. 28th

Ch. 5       7, 11, 16, 21, 30   +     I won't say. ---and Due Feb. 4

Exam 1 Friday Feb. 6

1) Physics---be clear about problem statements (especially cyop). Understand the deeper meaning. For example either relativistic coordinate or galilean coordinate transformations refer to taking AN EVENT (x,y,z, t) in one frame and describing the coordinates of the SAME EVENT (x',y',z',t') in another frame. If you had two different times in your cyop described within a single reference frame, then you were describing a more complicated situation with two events. We will learn velocity, momentum, KE, etc transforms. Be mindful of the physics.

2) Communication: Many comments: If a staple goes through the corner of your page, I can't (CAN NOT) read what is under that. Leave margins. Leave at least a margin between problems. Pencil writers, write hard and use a sharp pencil.....check with someone that they can glance at your work and read it. Cursive writers, similar to pencil, check and see that someone can read it at a glance.

Keep it clean--you all are pretty good about this---

Margins. Leave them alone (1 inch blank all around the problem, top, bottom, left, right). ONE SIDE OF PAGE ONLY. (why? You want room for your notes later, and the printing on two sides often bleeds through--making it harder to read)

PICTURES, PICTURES, PICTURES, ---NOT ARTWORK, BUT MEANINGFUL SKETCH.

3) Questions: Ask them early, ask them in class, be specific, ask your classmates, etc.

I tend to grade gently. I mark heavily. There are many points that can be cleaned up (look at your paper). Most of you have lots of room to improve your work by asking questions throughout the assignments. There have been many questions on ch. 3 hw already, but only a small fraction of what there should be. "More please".

4) CYOP: Your creativity is great, but the problems also need to be viable physics problems. Try them out on someone.

Exam 1 comments:

• Relativistic postulates and basic transforms (5)
• Basic matrix multiplication (5)
• Relativistic KE to classical KE (15)
• Use time dilation or length contraction--various (numbers---and I don't cook), invert gamma for speed (20)
• Velocity transformation (10) (numbers)
• Doppler 1, 2, 3 ----(25)---it should be easy to guess the three situations 123ABC. (numbers)
• Speed from gamma, KE, E, (20)--easy numbers