A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

A figure skater along a circular path of radius 5 m. If she coasts around one half of the circle, find (a) the magnitude of the displacement vector and (b) what distance she skated? (c) What is the magnitude of the displacement if she skates all the way around the circle?

  • This Question is Open
  1. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Do you know what is the difference between the "magnitude of the displacement vector" and "the actual distance skated" (parts a and b)?

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

    Magnitude of displacement is the straight line distance from the beginning of a path to the end of the path. What is the length of the straight line drawn from the beginning position to a point half way around the circle?

  3. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438648778741:dw|

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

    @mathstudent55 as far as I know, part b is half circumference of a circle (?) and a i don't know hehe

  5. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    In other words, part a is the diameter of the circle, part b is the half-circumference of the circle.

  6. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    For part c, she goes one full circle. She ends up where she started, so the magnitude of the displacement vector is zero. The distance is the circumference.

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

    @ospreytriple the half part of a circle is 5 m therefore, 2r=10 (?)

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

    Exactly. Good job.

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

    @ospreytriple Thanks :)

  10. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Part a: diameter = 2r Part b: half circumference = pi * r Part c: magnitude = 0; distance = circumference = 2*pi*r

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

    For the second question you need to calculate the actual length of the path. So it is half of the circumference of the circle. Can you calculate that?

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

    @mathstudent55 Thanks :)

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

    @ospreytriple I answered: 1/2 x 2 x pi x r therefore: 78.57 (?)

  14. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    1/2 * 2 * pi * r = pi * r = 3.14 * 5 m How do you get such a large number?

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

    @mathstudent55 1/2 x 2 x 22/7 x 5 x 5 hehe I don't know (?)

  16. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The radius, r, is not squared for the circumference. It is only squared for the area.

  17. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438649386383:dw|

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

    @mathstudent55 okay thanks :) So the final answer is 15.7 (?)

  19. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438649464150:dw|

  20. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Correct. That is the answer for part b.

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

    @mathstudent55 Thank you so much ^_^

  22. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Then for part c you need to do the same two things you did for parts a and b, but now for a full circle.

  23. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438649568860:dw|

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

    I get it. So for part c the answer is zero (?)

  25. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The figure above is for part c.

  26. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Part c has two parts. First, the magnitude of the distance vector is zero. Then the second part of part c is the distance traveled. That is the full circumference, so take your answer before, 15.7 m (half a circumference), and multiply it by 2.

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

    @mathstudent55 Thanks :)

  28. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You're welcome.

  29. 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.