A simple band brake performs on a drum of 600mm in diameter that is running at 200 r.p.m. The coefficient of friction is 0.25. The brake band has a contact at 270o one end is fastened to a fixed pin and the second end to brake arm 125 mm from the fixed pin. The straight brake arm is 750 mm long and placed perpendicular to the diameter that bisects the angle of contact.
(a) What is the pull required on the end of the brake arm to stop the wheel if 35 KW is being absorbed ? Find the direction for the minimum pull ?
(b) What width of steel band of 2.5 mm thick is needed for this brake of the maximum tensile stress is not to exceed 50 MPa.