GEO 702 Lecture 1: 01 Introduction

A .3 kg mass is suspended on a spring. In equilibrium the massstretches the spring 2 cm downward. The mass is then pulled anadditional distance of 1 cm down and released from rest. Write downits equation of motion.

a) y= (.03 m) sin (22.1 t)
b) y= (.01 m) sin (22.1 t)
c) y= (.01 m) cos (22.1 t)
d) y= (.03 m) cos (22.1 t)

W=ΔK+ΔU

W=.5(65)(7.7²-0)+(65)(-9.8)(0-3)

W=3837.925J

W=Fd

F=(3837.922)/(.01)

F=3.8x10⁵

^{The real answer is exactly half of this, why?}

A divice used since the 1940s to measure the b kick  01 recoil of the body due to heartbeats is the "ballistocardiograph'', What physics 

principle (s)are involved here to measure the force of cardiac contraction ? How might we construct such a device ?