Question

You hold a 1.80-N softball in your hand as shown in the figure. Consider your forearm and hand to be a uniform rod with a mass of 1.85 kg and the distance between the elbow joint and the ball in your hand is

2L = 22.5 cm.

Your biceps exerts an upward force of 12.0 N on the forearm and is attached at a distance of

d = 2.20 cm

from the elbow.

(a) Using the elbow joint as the axis of rotation, determine the magnitude of the net torque acting about the elbow due to the forearm, hand, and ball.
N · m

(b) In which direction will the forearm and hand rotate, if the net torque obtained in part (a) is nonzero?

counterclockwise no rotation    clockwise

Answer 1