Question

Question 5 of 5 1.0 Points Alpha performed a stepping exercise for 23 minutes onto a 16 inch box at a cadence of 108 bpm. Alpha weighs 225 lbs. Alpha's average Net VO2 was 3.17 LO2/min and his average VCO2 was 2.77 LCO2/min. Calculate Alpha's net mechanical efficiency during this bout of exercise. Round your answer to the first decimal place. 0A 17.9% (-) B. 17.2% ° C. 16.7% () D. 14.1% Reset Selection Mark for Review What's This? SavexSubmit for Grading

Answer 1

Calculate the output workusing the expression; Work - WxfxtxH Here, W is the weight of Alpha, t is time of stepping exercise, H is step height and f is frequency Substitute 225 lbs. for W, 23 minutes for t, 108bpm for f and 16in. for H. 1 kg Work 225 lbsx x108 bpm x 23 minutesx 16in.x_ 39.37 in. 2.205 lb -103010.1652kgm kgJ -103010.1652 kgmx0.0098 kgm 1009.5kJ Calculate the energy expenditure VO, using the expression; VO, 0.2f1.33 x1.8 x Hf) +3.5 16in.x 39.37 in -0.2(108)+1.33x1.8x 16in.xx108 +3.5 39.37 in. 21.6 +105.08+3.5 -130.18 mlof O,/kg/min

Calculate the total O, consumed during the exercise -130.18 mlof O,/kg/minx 2251bs x 2.205 lb - 305514.5 ml -30554.5 mlx 1000 ml - 305.511L 1L of oxygen consumed is equal to 5.6 kcal of energy. Thus, 305.52L contains O, 305.51x5.6 1710.856 kcal Convert the unit from kcal to kJ kJ O,-1710.856 kcalx 4.184 kcal 7158.221504 kJ Calculate Alpha's net mechanical efficiency. Work 7x100 1009.5__x100 7158.221504 kJ 14.1% Thus, the net mechanical efficiency is 14.1%