ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Recent Posts
What do you do?
by HotLine1. 10/16/17 07:22 PM
Good ol' copper pipe in the fuse holder trick
by HotLine1. 10/16/17 07:16 PM
Generator Cable Sizing
by HotLine1. 10/16/17 07:13 PM
Another generator question
by HotLine1. 10/16/17 07:02 PM
Thermal Imaging Camera upgrade
by SteveFehr. 10/15/17 08:15 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
241,326 Are you busy
177,273 Re: Forum
168,914 Need opinion
Who's Online Now
0 registered members (), 55 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#171072 - 11/19/07 07:01 AM reference distress  
Angel_Electric  Offline
Member
Joined: Jun 2007
Posts: 20
Fl.
First I attempted to post this question in the technical forum but was rejected so I hope its ok that I place this here for now. I'm currently attempting to delve into a book called Alternating Current Fundamentals / Sixth Edition(Delmar Thomson Learning), I'm hoping someone might have some form of familiarity with this text.Chapter 1 Achievement review Question #5(If the rotating line of figure 1-8 has a length of one unit,determine its projection or shadow on the x & Y Axes at 30 degrees, 45 degrees, 120 degrees,and 240 degrees.)Refer to Fig. 1-8 and appendices 4&5. I simply don't get what is expected of me, in the whole question. Any help would be appreciated


Work Gear for Electricians and the Trades

#171077 - 11/19/07 09:10 AM Re: reference distress [Re: Angel_Electric]  
n1ist  Offline
Member
Joined: Feb 2002
Posts: 183
Malden MA
Just guessing from your description:

You have 4 cases. In each case, there is a line of 1 unit long, one end at the origin (0,0) where the angle between the line and the x-axis is 30, 45, 120, and 240 degrees (one per case).

They want to know if you draw lines from the other end to the X and Y axes, where do they cross them?

The original line, the axis, and the projected line form a right triangle with the 1-unit line being the hypotenuse. The definitions of sine and cosine (sine = opposite/hypotenuse, cosine = adjacent/hypotenuse) will let you calculate the answer.

One thing to be careful of, most calculators expect the angles to be in radians, not degrees.


#171086 - 11/19/07 02:11 PM Re: reference distress [Re: n1ist]  
earlydean  Offline
Member
Joined: Dec 2003
Posts: 751
Griswold, CT, USA
I do believe the answer to the question is the shadow on the x-axis corresponds to a sine wave, and the shadow on the y-axis corresponds to a cosine wave.


Earl


Member Spotlight
mxslick
mxslick
Atomic City, ID USA
Posts: 803
Joined: October 2004
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 15 (0.004s) Memory: 0.7525 MB (Peak: 0.8757 MB) Zlib enabled. Server Time: 2017-10-17 02:04:29 UTC