(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 6 of 6

Thread: Please help; what this Question meaning

  1. #1

    Default Please help; what this Question meaning

    I don’t understand how to solve this question -

    “Find the sinusoid magnitude and phase “in degrees” at 0.5 ms for this

    V(t)= 5 sin (2π * 500 t + π/4 ) [V]


    Thanks alot ...
    Amy212

  2. #2
    DIY Member arfeller's Avatar
    Join Date
    Aug 2007
    Location
    Port Angeles, WA
    Posts
    77

    Default

    Quote Originally Posted by Amy 212 View Post
    I don’t understand how to solve this question -

    “Find the sinusoid magnitude and phase “in degrees” at 0.5 ms for this

    V(t)= 5 sin (2π * 500 t + π/4 ) [V]


    Thanks alot ...
    Amy212
    Is that symbol after the "2?" and "?/4" PI?
    And can we assume the units of t is seconds?
    Last edited by arfeller; 05-08-2008 at 01:45 AM.

  3. #3
    Plumber jimbo's Avatar
    Join Date
    Aug 2004
    Location
    San Diego
    Posts
    9,001

    Default

    This is a straight forward solution. You just don't have all the information.

    I don't specifically recognize or remember that equation from my electrical/electronic school days. But it would make sense if your "n" was pi. You have given t as 0.5 ms, so all you need to plug in a value for V and git'r'done.

  4. #4
    Aspiring Old Fart, EE, computer & networking geek Mikey's Avatar
    Join Date
    Nov 2005
    Location
    Central Florida
    Posts
    2,686

    Default

    The formula as given is a little confusing, what with that [V] term dangling out there. If we assume t in seconds, and [V] just some arbitrary constant, you could express your answer in terms of [V]. All you really have to do is find the value of the sine function for t=.0005 seconds, which turns out to be .707. Thus the answer would be 3.535[V], but again I have no idea how to interpret the [V] term...

    For t=.0005, the argument of the sine function evaluates to 0.5pi + pi/4 = 3*pi/4. Since 2pi radians = 360 degrees, the phase is 135 degrees. This is consistent with the value of the sine function, 0.707, which is the value of a sine function at any multiple of 45 degrees.

    Was [V] originally written as |V|, by any chance? That would make sense.
    Last edited by Mikey; 05-08-2008 at 02:14 PM. Reason: Removed the assumption that t was time

  5. #5

    Default

    Hi guys;

    I sorry;

    V(t)= 5 sin (2pi * 500 t + pi/4 ) [V]

    My problem i do not understand what "magnitude" mean?



    And thanks again.
    Last edited by Amy 212; 05-08-2008 at 11:23 AM.

  6. #6
    Aspiring Old Fart, EE, computer & networking geek Mikey's Avatar
    Join Date
    Nov 2005
    Location
    Central Florida
    Posts
    2,686

    Default

    Magnitude would be the value of the function. For example, the magnitude (value) of a sine wave can be anything from -1 to +1. In my answer above, the magnitude of the function V(t) for t=.0005 was 3.535.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •