The head injury criterion (HIC) is used to assess the likelihood of head injuries arising from various types of collisions; an HIC greater than about 1000 s is likely to result in severe injuries or even death. The criterion can be written as HIC = (aavg/g)2.5Δt, where aavg is the average acceleration during the time Δt that the head is being accelerated, and g is the free-fall acceleration. Shown is a simplified graph of the net force on a crash dummy’s 4.5 kg head as it hits the airbag during an automobile collision. What is the HIC in this collision?
