So here is the question I'm stuck on. A woman is reported to have fallen 112 ft from a building, landing on a metal ventilator box, which she crushed to a depth of 24 in. She suffered only minor injuries. Calculate the magnitude of her average acceleration while in contact with the box. I know average accel. = (delta v) / (delta t) I calculated the speed of the woman just before she collided with the box to be 84.664 ft/s. Although I'm a bit lost on how to calculate the avg. acceleration because I'm not sure what equation I should use to calculate (t).