1. The problem statement, all variables and given/known data A machine part consists of a thin 35.1-cm-long bar with small 1.81-kg masses fastened by screws to its ends. The screws can support a maximum force of 70.3 N without pulling out. This bar rotates about an axis perpendicular to it at its center. 2. Relevant equations Newton's 2nd law, a_rad=v^2/r 3. The attempt at a solution (What am I doing wrong?) The centripetal acceleration is v2/r=v2/0.351 m/s^2, so the net force on each mass is 1.81v^2/0.351 N ≤ 70.3 N Solving we get v ≤ ~3.69226 m/s, so the largest v is that. However, I'm being told this is wrong. However, the same problem with very similar numbers but different numbers had an answer of ~3.61 which is pretty close.