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: Solving for applied force to push an object up a ramp.

  1. Jun 17, 2010 #1
    A box, mass 100kg, must be pushed onto a table using an inclined plane 1.5 m high. The plane is 4 m long. If the pleane offers a frictional force equivalent to 10% the weight of the box, what force must be applied to move the box?

    What I tried:
    sin^-1(4/1.5) = 22.6
    100 * 9.8 = 980 N (fgrav)
    980cos22.6=904.77N (Fperpendicular)

    That's where I get stuck. I'm not sure if I'm even doing it right (However, I know the angle is).

    Please help. My exam is tomorrow.
  2. jcsd
  3. Jun 17, 2010 #2
    angle (theta)=sin^-1(1.5/4)=22.02 deg. (You take sin^-1 (4/1.5))

    Use summation F(x)=0
    friction and mg sin (theta) direction is downward . Applied force dirction is upward.Yes your friction is 98 N. No need to consider Y direction here.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook