To lift the barbell one time W=200 J She lifts 21 repititions a day and her body

Question

To lift the barbell one time W=200 J She lifts 21 repititions a day and her body uses a total energy of 1.7 x 104 J. How many 420 Calorie donuts can she eat a day to supply that energy? Please show work How many 420 Calorie donuts can she eat a day to supply that energy? Please show work A weightlifter works out at the gym each day. Part of her routine is to lie on her back and lift a 43 kg barbell straight up from chest height to full arm extension, a distance of 0.47 m. To lift the barbell one time W=200 J She lifts 21 repititions a day and her body uses a total energy of 1.7 x 10^4J. How many 420 Calorie donuts can she eat a day to supply that energy? Please show work

Explanation / Answer

solved a similar question already with different numbesr.. i put the question and the answer.. hope it helps!! :) A weightlifter works out at the gym each day. Part of her routine is to lie on her back and lift a 44kg barbell straight up from chest height to full arm extension, a distance of 0.50m. (A) How much work does the weightlifter do to lift the barbell one time? (B) If the weightlifter does 25 repetitions a day, what total energy does she expend on lifting? Assume 25% efficiency. (C) How many 490 Calorie donuts can she eat a day to supply that energy? ANSWER: A weightlifter works out at the gym each day. Part of her routine is to lie on her back and lift a 44kg barbell straight up from chest height to full arm extension, a distance of 0.50m. (A) How much work does the weightlifter do to lift the barbell one time? Work = force * distance Weight = 44 * 9.8 Work = 44 * 9.8 * 0.5 = 215.6 N-m = 215.6 J (B) If the weightlifter does 25 repetitions a day, what total energy does she expend on lifting? Assume 25% efficiency. Work = Energy Energy =215.6 J /rep * 25 rep = 5390 J if 100% efficiency Since she is only 25% efficient, she has to expend 4 * 5390 J = 21,560 J of energy to do 5390 J of work. (C) How many 490 Calorie donuts can she eat a day to supply that energy? 4.18 J = 1 calorie 21,560 J ÷ 4.18 J/cal = 5157.9 calories ÷ 490 cal /donut = 10.526 donuts If, you would like me to answer your questions in the future, request that I be one of your contacts. Then when you post a question, I will receive it via email. Otherwise I just search randomly for a question to answer. Thanks for the opportunity to be of help

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