Question
A machine part consists of a thin 40.0 cm long bar with small 1.15 kg masses fastened by screws to its ends. The screws can carry a maximum force of 75.0 N without pulling out. This bar rotates about axis perpendicular to it at its center.
A) As bar is turning at a constant rate on a horizontal, frictionless surface, what is utmost speed the masses can have without pulling out screws?
B) Presume machine is redesigned so that the bar turns at a constant rate in a vertical circle. Will one of screws be more likely to pull out when the mass is at the top of the circle or at bottom? Utilize a free-body diagram to see the reason.
C) Using result of part B, what is maximum speed the masses can have without pulling a screw?