While a person is walking, his arms (with typical lengths 70 cm measured from the shoulder joint) swing through approximately a 45 degree angle in 0.5 s. As a reasonable approximation, we can assume that the arm moves with constant speed during each swing. Find the magnitude of the force that the blood vessel must exert on the drop of blood. (I've already calculated the acceleration of 1.00 g drop of blood to be 1.7m/s^2.) I've tried using n-w = m(v^2/r). Its not going so well. Is this the correct equation? Can you get me started? Thank you.