Results 1 to 3 of 3

Math Help - Help with Trig. homework please

  1. #1
    Newbie
    Joined
    Jan 2010
    Posts
    7

    Help with Trig. homework please

    I have recently started my first trig class and Im kind of lost on a couple of the homework problems. If a wheel has a central angle of 157.8 degrees and it rotates 150.5 times per second determine the radians/hour using angular velocity and miles/hour using linear velocity.

    I dont even know what Im doing really. For the angular velocity problem I know in an hour it rotates 9030 times. I have to convert 157.8 degrees into radians and I did that and got 5.26pi/6. So Im not sure what to do next. I dont even know how to start the miles/hour problem. Can someone give me a hint please? Thanks.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    No one in Particular VonNemo19's Avatar
    Joined
    Apr 2009
    From
    Detroit, MI
    Posts
    1,823
    Quote Originally Posted by princesasabella View Post
    I have recently started my first trig class and Im kind of lost on a couple of the homework problems. If a wheel has a central angle of 157.8 degrees and it rotates 150.5 times per second determine the radians/hour using angular velocity and miles/hour using linear velocity.

    I dont even know what Im doing really. For the angular velocity problem I know in an hour it rotates 9030 times. I have to convert 157.8 degrees into radians and I did that and got 5.26pi/6. So Im not sure what to do next. I dont even know how to start the miles/hour problem. Can someone give me a hint please? Thanks.
    If the thing rotates \frac{150.5}{s} this implies that \omega=\frac{2(150.5)\pi{rad}}{s}

    Now the coversion to hours : \frac{301\pi{rad}}{s}\cdot\frac{60s}{hr}=?

    Wouldn't we need te radius of the wheel to determine linear velocity?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,116
    Thanks
    1000
    Quote Originally Posted by princesasabella View Post
    I have recently started my first trig class and Im kind of lost on a couple of the homework problems. If a wheel has a central angle of 157.8 degrees and it rotates 150.5 times per second determine the radians/hour using angular velocity and miles/hour using linear velocity.

    I dont even know what Im doing really. For the angular velocity problem I know in an hour it rotates 9030 times. I have to convert 157.8 degrees into radians and I did that and got 5.26pi/6. So Im not sure what to do next. I dont even know how to start the miles/hour problem. Can someone give me a hint please? Thanks.
    recheck the wording of the first problem. the 157.8 degree central angle has nothing to do with the problem, unless the corresponding arc length was given, so that you might find the wheel's radius (which you will need to find the linear velocity).

    to convert revolutions per second to rad/hr ...

    \frac{rev}{sec} \cdot \frac{2\pi \, rad}{rev} \cdot \frac{3600 \, sec}{hr}


    the relationship between angular velocity, \omega , and linear velocity , v , is v = r\omega
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Trig homework
    Posted in the Trigonometry Forum
    Replies: 0
    Last Post: December 1st 2008, 10:21 AM
  2. Trig homework
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: December 1st 2008, 04:41 AM
  3. trig homework, please help!
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: May 27th 2008, 10:26 AM
  4. Please Help! Trig homework....
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: April 6th 2008, 05:55 PM
  5. need homework help-trig
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: March 27th 2008, 06:19 PM

Search Tags


/mathhelpforum @mathhelpforum