Results 1 to 3 of 3

Math Help - Work question (involving vectors)

  1. #1
    Newbie
    Joined
    Dec 2008
    Posts
    24

    Work question (involving vectors)

    I can't seem to get the correct answer for this problem. I'm not sure where i'm going wrong.

    "A tow truck drags a stalled car along a road. The chain makes an angle of 30 with the road and the tension in the chain is 1100 N. How much work is done by the truck in pulling the car 1 km?"

    Thanks in advance.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member AllanCuz's Avatar
    Joined
    Apr 2010
    From
    Canada
    Posts
    384
    Thanks
    4
    Quote Originally Posted by sj9110 View Post
    I can't seem to get the correct answer for this problem. I'm not sure where i'm going wrong.

    "A tow truck drags a stalled car along a road. The chain makes an angle of 30 with the road and the tension in the chain is 1100 N. How much work is done by the truck in pulling the car 1 km?"

    Thanks in advance.
    Work = (Force x Distance)

    Have you considered decomposing your chain into a right angle triangle with the road (i.e. 1100 N is the hypotenuse)?

    I don't have a caclulator on me but this should be relatively simple, once you find the component along the road multiply by the distance (i.e. 1km).

    Also note, the answer will depend on if the Truck is accelerating or not. If it is, we need to involve work-energy theorem but if not, the above should suffice.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2008
    Posts
    24
    yeah, i think my error is in the rounding. it says to the nearest ten thousand. I did 1100cos(30) = 952.6279442 = F

    W = 952.6279442 (D) (Where D = 1000) (converting km to m)
    W = 952627.9442

    The answer I gave (incorrectly) was 953,000.. now I see this is only to the thousand, not ten thousand, so I guess it should be 950,000.

    If someone could confirm this I would be very grateful, I only get one more chance at it.

    Thanks.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Work done (Question on Vectors)
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: May 23rd 2011, 05:58 PM
  2. Replies: 4
    Last Post: February 17th 2009, 03:33 PM
  3. [SOLVED] Vectors: Work Question(Dot Product)
    Posted in the Advanced Applied Math Forum
    Replies: 2
    Last Post: February 16th 2009, 01:31 PM
  4. Question involving vectors
    Posted in the Calculus Forum
    Replies: 0
    Last Post: February 5th 2008, 04:12 AM
  5. Strange question involving vectors
    Posted in the Calculus Forum
    Replies: 0
    Last Post: February 5th 2008, 04:10 AM

Search Tags


/mathhelpforum @mathhelpforum