Welcome to blog help for PHY 122! Here's how it works.
For each homework question and lab report we will make a post, this will probably contain a few tips on what the problems are about and how to solve them. If you are stuck on something then instead of emailing us directly you should post a comment in reply to the relevant post. We will try to guide you through tough points and help you understand the problems and the concepts behind them.
Wednesday, September 29, 2010
Chapter 19, Problems 1-4
In the first problem, the range between maximum and minimum comes from the relative direction of the magnetic field and the electron's motion.
3 comments:
Anonymous
said...
I'm having a difficult time with t time with problem #4. I'm not sure of how to set up an equation for this problem and the textbook isn't helping.
WebAssign Prob. #4 for Ch19 HW is Prob. 20 of SV8 Ch19 on p. 657. There you see it relates to Ch19.4 (Sec. 4 of Ch19). Have you gone over everything in that section, particularly Example 19.3? Maybe your problem is the (linear) mass density of the wire, 0.040 kg/m in SV8 but probably a different value in your WebAssign problem. For such problems I just let the wire have a convenient length L, L=1 m, say. Then I know its mass M. It's subject to gravity so there is a downward weight force W=Mg. You need a upward magnetic force to counteract W. Since the magnetic force depends on the length of the wire, use the same length L from above. Go through Example 19.3 (again), and I think you'll get it. Good luck.
3 comments:
I'm having a difficult time with t time with problem #4. I'm not sure of how to set up an equation for this problem and the textbook isn't helping.
WebAssign Prob. #4 for Ch19 HW is Prob. 20 of SV8 Ch19 on p. 657. There you see it relates to Ch19.4 (Sec. 4 of Ch19). Have you gone over everything in that section, particularly Example 19.3? Maybe your problem is the (linear) mass density of the wire, 0.040 kg/m in SV8 but probably a different value in your WebAssign problem. For such problems I just let the wire have a convenient length L, L=1 m, say. Then I know its mass M. It's subject to gravity so there is a downward weight force W=Mg. You need a upward magnetic force to counteract W. Since the magnetic force depends on the length of the wire, use the same length L from above. Go through Example 19.3 (again), and I think you'll get it. Good luck.
By setting Length to 1m that helped. Thank you.
Post a Comment