It is given that the plane \(B C\) is smooth and that the particles are released from rest.
Find the tension in the string and the magnitude of the acceleration of the particles.
It is given instead that the plane \(B C\) is rough. A force of magnitude 3 N is applied to \(Q\) directly up the plane along a line of greatest slope of the plane.
Find the least value of the coefficient of friction between \(Q\) and the plane \(B C\) for which the particles remain at rest.