A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Find the work W done by a force of 5 pound acting in the direction of 45 degree to the horizontal in moving an object 7 feet from (0,0) to (7,0) W = ? foot-pounds

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Also, this is dealing with vectors F and magnitude

  2. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok, This is what I got. One sec

  3. mathmate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(work~done, W=\textbf{F.D}=FDcos(\theta)\) where \(\theta\) is the angle between \(\textbf{F}~and~\textbf{D}\). W is a scalar.

  4. mathmate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1435713093544:dw|

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    F = 5(cos ai + sin aj) cos 45 + sin 45 \[ \huge 5(\frac{\sqrt{2}}{2}i + \frac{\sqrt{2}}{2}j ) \] \[ \huge \frac{5\sqrt{2}}{2}i + \frac{5\sqrt{2}}{2}j \]

  6. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Now I guess the W is the magnitude of force to the distance?

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Or magnitude time distance

  8. mathmate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    It is a dot product. So you need to put the distance as a vector as well, then proceed with the dot product!

  9. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So..... \[\huge (\frac{5\sqrt{2}}{2}i + \frac{5\sqrt{2}}{2}j) * 7i \] \[\huge (\frac{5\sqrt{2}}{2}(7) + \frac{5\sqrt{2}}{2}(0)) \] \[\huge (\frac{5\sqrt{2}}{2}(7) + \frac{5\sqrt{2}}{2}(0)) \] \[\huge \frac{5\sqrt{2}}{2}(7) \] \[\huge W = \frac{35\sqrt{2}}{2} \] Correct?

  10. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep that looks good

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thanks!

  12. mathmate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yep, that's right.

  13. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.