A truck pulls boxes up an incline plane. The truck can exert a maximum force of 5,600N. If the plane's incline is 2π3 and the coefficient of friction is 76, what is the maximum mass that can be pulled up at one time?

1 Answer
May 1, 2016

979 kg

Explanation:

enter image source here

Note, by definition, an inclined plane cannot have an inclination more than π2. I take the angle is measured from positive x-axis, so it is just θ=π3 the other way.

here f is the applied force, NOT the frictional force.

So, as we can easily observe in the picture, the forces that oppose will be (m is expressed in kg):

  1. gravitational pull: mgsinθ=9.8×32m=8.49mN

  2. frictional force, opposite to the direction of tendency of movement: μmgcosθ=76×9.8×12mN=5.72mN

Hence total is: (8.49+5.72)mN=14.21mN

So, for the truck the to be able to pull it up, the maximum force it can exert must be more than this:

5600N>5.72mNm<979kg