1. The forearm in Fig. 10 52 accelerates a
3.6-kg ball at 7.0 m /s2 by means of the triceps
muscle, as shown. Calculate (a) the torque needed, and (b) the force that must
by the triceps muscle. Ignore the mass of the arm.
2. A 0.72 m diameter solid sphere can be
rotated about an axis through its center by a torque of 10.8m N which
accelerates it uniformly from rest through a total of 180 revolutions in 15.0
s. What is the mass of the sphere?