Question

The total cross-sectional area of the load-bearing calcified portion of the two forearm bones (radius and ulna) is approximately 2.20 cm2 . During a car crash, the passenger attempts to brace himself with his hand such that his forearm is perpendicular to the dashboard. His forearm is slammed against the dashboard, hand first. The arm comes to rest from an initial speed of 80.0 km/h in 4.90 ms. If the arm has an effective mass of 3.00 kg, what is the compressional stress that the arm withstands during the crash?

Answer 1