Calculate the magnitude of the force in the back muscles needed to support the upper back plus the box (m upper body = 65 kg , m box = 20 kg) 2. calculate the magnitude of the force Fv exerted by the vertebrae on the spine at the indicated pivot point

 

10 cm Zo Pivot point 10% F spi 39 45 cm 60 cm 61 CGub Wub Cobox Wook