Practice It

Use the worked example above to help you solve this problem. A student eats a breakfast consisting of a bowl of cereal and milk, containing a total of $3\mathrm{.}35{10}^2$ Calories of energy. He wishes to do an equivalent amount of work in the gymnasium by doing curls with a $23\mathrm{.}0$ kg barbell $($see figure below$).$

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How many times must he raise the weight to expend that much energy? Assume that he raises it through a vertical displacement of $0\mathrm{.}400$ m each time, the distance from his lap to his upper chest.

Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. times

Exercise