A small block B fits inside a lot cut in arm OA which rotates in a vertical plane at
a constant rate. The block remains in contact with the end of the slot closest to A
and its speed is 1.4 m/s for 0 150 . ≤≤ ° θ Knowing that the block begins to slide
when θ = ° 150 , determine the coefficient of static friction between the block and
the slot.