Page:NTSB RAR-77-10.pdf/36

 — 33 - APPENDIX

From a momentum balance just prior and after impact

8 V0 2

8 . 6 1 Hi = VF igl wi + v E w'i

1 i=1

Substituting known data into this equation and solving for VP (the velocity of the impacting consist immediately after the collision)

VF = 37 in [sec

The kinetic energy due to this velocity is 2 8 Ev ‘ (V? l28) .2 W1 i—l Substituting into this equation

E = 752,000 in./lb

V This results in an error of approximately 5 percent in the total collision energy and only an error of 2.6 percent in the closing velocity A more accurate prediction of the closing velocity

would be

Vo = g;§ mph.