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A 75-kg sprinter accelerates from rest to a speed of 11.0 m/s in 5.0 s.?. a) Calculate the mechanical work done by the sprinter during this time. . I know W=0.5mv^2 = 4538 J . . b)Calculate the average power the sprinter must generate. P=W/t= 908W. . c) If the sprinter converts food energy to mechanical energy with an efficiency of 25%, at what average rate is he burning Calories?.

Respuesta :

meerkat18
a. Work = KE = 0.5mv²
   Substituting the known values,
                                  KE = 0.5(75 kg)(11 m/s)² = 4537.5 J
b. Power = W / t. Substituting,
                                   P = 4537.5 J / 5 s = 907.5 W
c. Only 25% is absorbed. So, the sprinter only absorbed 226.875 J per second which is equal to 54.20 calories per second.