Chapter 7, Problem 60P

* BIO EST Exercising so you can eat ice cream You curl a 5.5-kg (12 lb) dumbbell that is hanging straight down in your hand up to your shoulder. (a) Estimate the work that your hand does in lifting the dumbbell. (b) Estimate the average mechanical power of the lifting process. Indicate any assumptions used in making the estimate. (c) Assuming the efficiency described at the end of Problem 7.59, how many times would you have to lift the dumbbell in order to burn enough calories to use up the energy absorbed by eating a 300-food-calorie dish of ice cream? (Problem 7.59 provides the joule equivalent of a food calorie.) List the assumptions that you made.