The 180-lb exerciser is beginning to execute a bicep curl. When in the position shown with his right elbow fixed, he causes the 20-lb cylinder to accelerate upward at the rate g/4. Neglect the effects of the mass of his lower arm and estimate the normal reaction forces at A and B. Friction is sufficient to prevent slipping.

Transcribed Image Text:

20° G. 62" 20 lb A 10" 10"-14"-