1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How long does it take to push this block at an angle?

  1. Feb 20, 2017 #1
    1. The problem statement, all variables and given/known data
    A 100 kg block is pushed across a level frictionless surface at a 60 degree angle, with a force of 20 newtons. How many seconds does it take to go 100 meters?

    m = 100kg
    Mu = 0


    2. Relevant equations
    F = MA

    3. The attempt at a solution
    I sketched out the problem on my paper here, showing the downward angle force of 20N as Fx, and then the angle of 60 degrees being theta. From there it just turned into a mess of equations, some of which may be right, others which may not, and I was wondering if I did this problem correctly.

    JcCVb70.jpg
     
  2. jcsd
  3. Feb 20, 2017 #2

    Student100

    User Avatar
    Education Advisor
    Gold Member

    You have the wrong equation for the last part. What is kinematic equation for position?
     
  4. Feb 20, 2017 #3

    gneill

    User Avatar

    Staff: Mentor

    The problem is vague in that it doesn't specify how the angle is to be measured. Is it measured from the vertical? From the horizontal? It makes a difference.
     
  5. Feb 20, 2017 #4

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    .. and is its vertical component up or down?
     
  6. Feb 21, 2017 #5
    Welcome to my world with my physics professor that drives me insane. I believe it's supposed to be how it is in the attached drawing. 60 degrees upward from the x axis.
     
  7. Feb 21, 2017 #6

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The drawing has it acting downward from 30 degrees above the x axis. I assume that is what you mean.
    Please respond to Student100's observation, that your equation D=at is wrong.
     
  8. Feb 21, 2017 #7
    Ohh, it's D = InitialVelocity*Time + 0.5a*t^2, isn't it?
     
  9. Feb 21, 2017 #8

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Yes.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: How long does it take to push this block at an angle?
Loading...