Question 74
A brick of weight 10 N lies on a rough plane inclined at an angle of 30° 30°\,30° to the horizontal. A horizontal force of magnitude 12 N acts on the brick, in the vertical plane containing a line of greatest slope. The brick is in equilibrium, on the point of slipping up the plane.
a.[5]
Find the coefficient of friction between the brick and the plane.
b.[2]
The 12 N force is now removed. Determine whether or not the brick moves.