A jogger with mass m = 75 kg uses energy at a rate of P = 518 W when she jogs on horizontal ground at a constant speed of s = 3.4 m/s. The efficiency of her "human engine" however, is e = 0.28. (In other words, the power used for locomotion is e = 0.28 times the total power.)

A) Enter an expression, in terms of defined variables, for the stress, S, that each nail will need to sustain at a temperature T_s.

B) What is the rate of energy expenditure when she jogs up the slope, in watts?