Very large accelerations can injure the body, especially if they last for a considerable length of time. the severity index (si), a measure of the likelihood of injury, is defined as si = a5/2t, where a is the acceleration in multiples of g and t is the time the acceleration lasts (in seconds). in one set of studies of rear end collisions, a person's velocity increases by 12 km/h with an acceleration of 35 m/s2.(a) what is the severity index for the collision? (s)(b) how far does the person travel during the collision if the car was initially moving forward at 7.0 km/h? (m)