A rough plane is inclined to the horizontal at angle α\alphaα. A block of mass m m\,m kg is placed on the plane and remains in equilibrium at the point of sliding down the plane. The coefficient of friction between the block and the plane is 0.10
Show that the magnitude of the normal reaction of the plane on the block is mgcosα mg\cos\alpha\,mgcosα N.
Hence find the value of α\alphaα.
The block is now projected with speed 0.3ms-1 down a line of greatest slope of the plane. Describe the motion of the block, giving a reason for your answer.
108 exam-style questions on Edexcel A Level Maths Forces and Friction, covering 5.1 Resolving Forces, 5.2 Inclined Planes, and 5.3 Friction. Each one has a worked solution and a mark scheme showing where the marks go.