The quarter-circular slotted arm oa is rotating about a horizontal axis through point o with a constant counterclockwise angular velocity ω = 7 rad/sec. the 0.1-lb particle p is epoxied to the arm at the position β = 60°. determine the tangential force f parallel to the slot which the epoxy must support so that the particle does not move along the slot. the value of r = 1.4 ft.