5) [Work Done] A weightlifter has a basal metabolic rate of 80.0 W. As he is

working out, his metabolic rate increases by about 650 W.

a) How many hours does it take him to work off a 450-Calorie bagel if he stays

in bed all day?

b) How long does it take him if he's working out?

c) Calculate the amount of mechanical work necessary to lift a 120 kg barbell


d) 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 W during the exercise?

e) Could he actually do repetitions at the rate found in part (d) at the given

metabolic level? Explain.