(Solved): 17-18-19-20 please A weightlifter has a basal metabolic rate of 72.9W. As he is working out, his ...

A weightlifter has a basal metabolic rate of $72.9\mathrm{W}$. As he is working out, his metabolic rate increases by about $650\mathrm{W}$. Answer the following: 17) How many hours does it take him to work off a 450 Calorie bagel if he's working out? a) $5\mathrm{h}$ b) $55\mathrm{h}$ c) $0.72\mathrm{h}$ d) $0.001\mathrm{h}$ 18) Calculate the amount of mechanical work necessary to lift a $109\mathrm{kg}$ barbell $1.90\mathrm{m}$. a) $5.9\mathrm{J}$ b) $778\mathrm{J}$ c) $2030\mathrm{J}$ d) $?0.25\mathrm{J}$ 19) He drops the barbell to the floor and lifts it repeatedly. How many times per minute must he repeat this process to do an amount of mechanical work equivalent to his metabolic rate increase of $650\mathrm{W}$ during exercise? a) 19.2 b) 0.25 c) 101 d) 2.5 20) Two dozen apples is how many moles of apples? a) 0.45 b) $4.89\times 10^{?4}$ c) $4.0\times 10^{?23}$ d) $1.0\times 10^{?24}$