460 BELL SYSTEM TECHNICAL JOURNAL 



n 0,1,2,3, ■■■ . 



P Force transmitted through cushioning. 



Po Asymptotic value of force transmissible through cushioning with hyper - 

 bolic tangent elasticity. 



Pm Maximum force exerted on packaged article by cushioning. 



Pn In Section 1.15, the load that produces displacement {x2)n- 



R Force between package and floor. 



r Coefficient of cubic term in load-displacement function for cushioning 

 with cubic elasticity. 



s, t, u The direction cosines of the acceleration direction with respect to the 

 normals to the faces of the package frame. 



sn The elliptic sine function. 



7*2 The period of vibration of the packaged article on its cushioning. 



t Time coordinate. 



/' t 



to Time of first contact of package with floor. 



tm Time at which maximum displacement or acceleration occurs. 



tr Time at which package leaves floor on rebound. 



t. Time at which the displacement reaches ds- 



u Displacement in x direction. 



V Approach velocity. 



Wz Weight of packaged article. 



Wz Weight of outer container. 



X Xi — X2; relative displacement of lui with respect to m-i. 



X Xi — X2. 



X Xi — X2- 



x' Relative displacement of m\ v.ith respect to mi at time t' . 



xo In the tension spring package, the perpendicular distance from an inner 

 spring support point to the nearest plane, perpendicular to the displace- 

 ment direction and containing four outer spring support points. 



Xi Displacement of nii. 



xi Velocity of nii. 



Xi Acceleration oinii. 



Xi Displacement of m2- 



X2 Velocity of m2- 



