I have absolutely no idea how to do this problem and I need help with steps, formulas/equations, etc. So, here it goes! David Purley, a racing driver, survived deceleration from 173 km/h to 0 km/h over a distance of 0.660 m when his car crashed. Assume that Purley's mass is 70 kg. What is the average force acting on him during the crash? Compare this force to Purley's weight. Please help!! Thanks!