4. Iosephine Bruin sometimes rides her bicycle home from UCLA, which involves a commute of 3 miles and an elevation gain of 500 ft. a. If Iosephine plus her bike weigh 150 lbs, calculate how much work against the Earth's gravitational eld she would need to accomplish just to raise her and her bike 500 feet above UCLA (in Joules]. If [osephine coasts on her bicycle all the way down from her house to UCLA, and all her gravitational potential energy were converted to kinetic energy, estimate how fast her bike would be traveling [in mph] as she rolls into campus. If the efciency of Iosephine's muscles is approximately 20%, estimate how many food calories (kilo-calories) she would need to consume to yield the same amount of work you calculated in Part a. If [osephine rides at an average speed of 12 miles per hour and accomplishes 100 watts of useful power while hiking, estimate how many food calories [kilo-calories) she would need to consume to ride home from school, including the inefciency of her muscles, but neglecting the potential energy gain. Iosephine's favorite food is breakfast cereal. Use the nutrition information on the side of a cereal box to estimate how many ounces of cereal she would need to eat to provide the amounts of energy you calculated in Parts c and (:1. Explain why the amount of cereal you estimated in Part e. are underestimates for the total amount of cereal that [osephine would need to eat to produce enough energy to bike home