A 324 lb. man rides a roller coaster and suffers a brain injury.

What is the force with which the 324 man is assaulted if the roller coaster accelerates  from 0 to 54 mph in 4 seconds and generates 4.5 g's during acceleration.

Impulsive inertial loading creates injury upon contact between his head and the headrest during deceleration.  It upon deceleration that the impact occurs.  What is the level of the force created upon this 324 man during this roller coaster ride? Don't know the rate of deceleration. Lim's are used to power the roller coaster which "shoot" it out of a starting agte. It goes through 30 vertical tuyrns, 25 compound turns and 4 inversions.

If the 4.5 g's exert 445.44 (appx.) newtons on a person of average weight 70 kg p, i.e. person, what is thr force exerted upon a person of the weight stated above. Give me a simple layman's example for a 324 pound man.  Like 445 newtons operating upon a 70kg person is like a person of that normal weight dropping 98.94 feet (appx) under normal gravitational conditions.