1. The problem statement, all variables and given/known data An "energy bar" contains 22 g of carbohydrates. If the energy bar was his only fuel, how far could a 68 kg person walk at 5 km/h? Mass(person) = 68 kg; v = 5km/h; 22g carb = 4 Cal/1 carb = 88 Cal; P(power of man walking) = 380W (this is derived from my textbook). 2. Relevant equations How long is the time interval that the man walks at; what is the KE of the man due to his efficiency. 3. The attempt at a solution velocity needs to be converted to m/s rather than km/h, so 5km/h*1000m/1km*1h/60s=83m/s. (This seems incorrect to me, but I don't understand how the answer would be different). 22g carb* 4Cal/1 Carb= 88 Cal; 88 Cal*4190J/1 Cal = 368720J; 368720 = Ecarb (I am also confused in this portion of the problem; does 1 carb = 1 Cal or 1 cal? Am I multiplying by 4.19J for 1 cal or 4190 for 1 Cal?) efficiency = output/input; e = KE/Ecarb; KE = Ecarb*e; KE = 368720* .25 (.25 for the efficiency of a person, derived from book/lecture); KE = 92180 J. P= KE/time interval; time interval = KE/P; t = 92180J/380W; t= 242.57s. displacement=velocity*time interval; d = 83m/s*242.57s; d=20133.31m. I know this final answer for displacement is completely wrong, but I cannot figure out where I made my mistakes in my calculations; I believe I am just setting the problem up incorrectly. Can somebody help me out? Thanks!