A 10.0 kg mass is suspended on an incline by a rope connected to a wall as shown in the diagram to the right.

Question

A 10.0 kg mass is suspended on an incline by a rope connected to a wall as shown in the diagram to the right. The coefficients of static and kinetic friction between the mass and the incline are 0.55 and 0.40, respectively. 

a) Draw a free-body diagram of the mass.

b) Determine the tension of the rope.

c) If the rope is cut, determine if the mass makes it to the bottom of the incline and if so how long it takes to reach the bottom. Assume the mass is 2.40 m from the bottom of the incline. 

diagram cant be shown: 50 degrees

Answer 1

Hi Elle C.,

Use the coefficient of static friction to compute how much of the mass's gravitational force is nullified along the incline. The remainder (decomposed properly into normal and tangential vectors) appears as rope tension to hold the mass in position. If the mass has a vector force down the plane greater than the coefficient of static friction, then it will start to slide down when released, but you must then use the kinetic friction to calculate the net force and hence the net acceleration.

-- Cheers, -Mr. d.