9. As shown in Fig. B9, a block of mass m2=2.1 kg sits on an inclined plane with angle 35 degrees . The coefficients of static and kinetic friction between the block and the plane are unknown. The block is attached to a rope, which is hung over a frictionless and massless pulley and attached to a hanging mass m1.
(a) The block my is on the verge of sliding, when the hanging mass is increased to m1=1.6kg.
01. find the coefficient of static friction.

As shown in Fig. Bob, an identical block (with mass m2) is placed on top of the block on the inclined plane. The hanging mass m1 remains unchanged. The two blocks on the inclined plane are sliding down the incline with the same acceleration a=0.31 m/s^2
Find
02.the coefficient of kinetic friction.
03.what is the minimum value of the coefficient of static friction between the two identical blocks (m2) so that they move together?