While a person is walking, his arms swing through approximately a 45° angle in .530s. As a reasonable approximation, we can assume that the arm moves with constant speed during each swing. A typical arm is 70.0 cm long, measured from the shoulder joint. (a) What is the acceleration of a .800 gram drop of blood in the fingertips at the bottom of the swing?

Question

While a person is walking, his arms swing through approximately a 45° angle in .530s. As a reasonable approximation, we can assume that the arm moves with constant speed during each swing. A typical arm is 70.0 cm long, measured from the shoulder joint.  (a) What is the acceleration of a .800 gram drop of blood in the fingertips at the bottom of the swing? 
1.54m/s^s i got correct

(b) Find the force that the blood vessel must exert on the drop of blood in part a.

im having touble solving this problem and part c

(c) What force would the blood vessel exert if the arm were not swinging?

i know the formula i use is F=ma

Bot · Answer

First, let's find the mass of the drop of blood.
Mass = 0.800 g = 0.0008 kg

(b) Now, we can find the force exerted by the blood vessel on the drop of blood using F = ma.
F = (0.0008 kg)(1.54 m/s²) = 0.001232 N

(c) When the arm is not swinging, the only force acting on the drop of blood is gravity. To find the force, we can use F = mg.
F = (0.0008 kg)(9.8 m/s²) = 0.00784 N