PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Linear Momentum · Linear Momentum
Problem
In a materials test, two different helmet liners are struck by a headform (a rigid model of a human head) of mass 5.0kg moving at 6.0ms−1 straight toward each liner and coming to rest without rebounding.
• Liner X brings the headform to rest in 5.0ms.
• Liner Y brings the headform to rest in 15ms.
Medical studies suggest that an average impact force above 4.5×103N greatly increases the risk of concussion.
(a) Determine the magnitude of the change in momentum of the headform during the impact.
(b) Calculate the magnitude of the average force exerted on the headform by each liner.
(c) Based on your calculations and the medical threshold, evaluate whether each liner is likely to keep the average impact force below the danger level.
(d) Recommend which liner should be adopted for a new helmet design and provide two pieces of evidence from your analysis to support your recommendation.