While a person is walking, his arms swing through approximately a 45.0^\circ angle in 0.520s . As a reasonable approximation, we can assume that the arm moves with constant speed during each swing. A typical arm is 70.0{\rm cm} long, measured from the shoulder joint.
1- What is the acceleration of a 1.60 gram drop of blood in the fingertips at the bottom of the swing?
2- Find the force that the blood vessel must exert on the drop of blood in part (a).
3- What force would the blood vessel exert if the arm were not swinging?