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!

Homework Help: Velocity of block as it hits a table sliding down a ramp?

  1. Dec 6, 2009 #1
    1. The problem statement, all variables and given/known data

    A block of steel is placed 120cm from the end of a sheet of metal. The sheet is raised just until the block begins to slide, which occurs when the block as 35cm above the surface of the table. the block is allowed to slide freely down the sheet until it slides onto the table. If the coefficient of friction is 0.20, what is the velocity of the block as it hits the table?

    2. Relevant equations

    Fxnet= Fg - Ff

    Fynet= Fn + Fg = 0

    3. The attempt at a solution

    Okay so I know that the angle would be 17 using trig.. But I don't exactly know how the masses cancel out here since we aren't given a mass. I know I have to find the acceleration of the block, and by finding that, I can find the final velocity using one of the five sisters. What I started out with was..

    Fxnet = Fg + Ff
    = mgsinθ + (Mu x Fn)
    = mgsinθ + (Mu x mgcosθ)
    = sin θ + (mu x cosθ) <--The thing is I'm not sure if I can do this or not..
    =sin 17 + (0.2)(cos17)
    = 0.1 N

    then I don't know what to do after this..
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted