6 A block \(B\) of weight 10 N is projected down a line of greatest slope of a plane inclined at an angle of \(20 ^ { \circ }\) to the horizontal. \(B\) travels down the plane at constant speed.
- (a) Find the components perpendicular and parallel to the plane of the contact force between \(B\) and the plane.
(b) Hence show that the coefficient of friction is 0.364 , correct to 3 significant figures.
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\(B\) is in limiting equilibrium when acted on by a force of \(T \mathrm {~N}\) directed towards the plane at an angle of \(45 ^ { \circ }\) to a line of greatest slope (see diagram). Given that the frictional force on \(B\) acts down the plane, find \(T\).