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* BIO Leg injuries during car collisions During a car collision, the knee, thighbone, and hip can sustain a force no greater than 4000 N. Forces that exceed this amount could cause dislocations or fractures. Assume that in a collision a knee stops when it hits the car’s dashboard. Also assume that the mass of the body parts stopped by the knee is about 20% of the total body mass. (a) What minimum stopping time interval is needed to avoid injury to the knee if the person is initially traveling at 15 m/s (34 mi / h)? (b) What is the minimum stopping distance?
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