Question

Assuming a typical efficiency for energy use by the body, how many slices of pizza must you eat to walk for 3.0h at a speed of 5.0 km/h? Assume that your mass is 68 kg,metabolic power of 68 kg individual walking at 5 km/h is 380 W , and the energy content of slice of pizza is 1260 kJ.

Number of Slices of pizza=---------

Answer 1

On average, human body needs 380 W of power for walking at 5 km/hr. That means human body expenses 380 J of energy per second for walking at 5 km/hr Simplification gives the speed of human is 1.39 m/s. That means for walking 1.39 m, energy of 380 J is needed. For three hours of walking, total distance to be walked is, d 1.39 m/s) (3) (3600 s) 15012 m For 1.39 m of walking, energy expensed is 380 J. therefore, for a total distance of 15012 m; the amount of energy needed is, 380 J 1.39 m E- (15012 m 4,104,000 J 4104000 J 1260000 J 3.26 Therefore, total pizza slice needed is slightly more than 3