A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

abdullah1995

  • one year ago

A block weighing 300 N slides downwards on the angled surface shown at an initial velocity of 2.5 m/s. At t = 0, a force P with the given orientation is applied until the block stops. Knowing that it took 5 seconds for the block to stop and that the coefficient of kinetic friction μk = 0.1, determine the magnitude of P (picture included in the post)

  • This Question is Closed
  1. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1438818371044:dw|

  2. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    First i broke the forces into components. Added the Fn and Friction force on the diagram and labelled 300N force acting downwards. Once i broke the forces into components i got two equations, one for forces acting on the y-axis and the second for forces acting on the x-axis. -0.4226P + Fn - 281.90 = 0 ---------- Equation (1) 0.9063P - F(f) +102.606 = 0 ---------- Equation (2) Note that F(f) is force of friction. Then i knew that F(f) = Fn x 0.1 from the question so i replaced it F(f) with it. -0.4226P + Fn - 281.90 = 0 0.9063P - 0.1Fn +102.606 = 0 After this i solved these two equations simultaneously and found the value of P. My question/confusion is regarding all the other information given in the question, such as the initial velocity, time etc. I feel like i have done something wrong here. Any guidance would be highly appreciated.

  3. johnweldon1993
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Hint* If the sum of the forces in the 'x' direction = 0...the block would never have moved. this is a dynamic problem not statics your 'x' equation should be equal to "ma"

  4. johnweldon1993
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    You have the times and velocities in order to solve for 'a' and use it to find your 'P'

  5. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ah ok i got it Thanks a lot ! Can you please help me with one more problem?

  6. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @johnweldon1993

  7. johnweldon1993
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    If I can of course!

  8. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    1 Attachment
  9. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I think i have done part A, but i am completely stuck on part B :/

  10. johnweldon1993
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    First, can you post what you got from part A

  11. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    BE: -4i + 8j -8k ---> BE = 12m |dw:1438834319191:dw|

  12. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    L(i) + 6(j) -8(k) ---> CD = \[\sqrt{L^2 +100}\] L|dw:1438834536640:dw|

  13. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    this is what i have.

  14. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @johnweldon1993

  15. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @johnweldon1993 don't leave me alone lol, i need help. Please help me :(

  16. abdullah1995
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @johnweldon1993 are you still here?

  17. 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.