Very large forces are produced in joints when a person jumps from some height to the ground. (a) Calculate the force produced if an 80.0-kg person jumps from a 0.600-m-high ledge and lands stiffly, compressing joint material 1.50 cm as a result. (Be certain to include the weight of the person.) (b) In practice the knees bend almost involuntarily to help extend the distance over which you stop. Calculate the force produced if the stopping distance is 0.300 m. (c) Compare both forces with the weight of the person.