Question

Thermal question

A 60-kg hiker plans to climb Mt Kosciuszko (2228 m) starting from Thredbo (1365m). Assume that she is 25% efficient at converting chemical energy from food into mechanical work, and that essentially all the work goes into the vertical climb. (a) (3 marks) With reference to the data above, how many servings of Nutrigrain should she eat to provide enough energy for the climb? (b) (6 marks) Climbing a mountain warms you up, and makes you sweat one of your body's ways of dissipating heat. Cells in your muscles convert chemical energy from food (in the form of adenosine triphosphate) into contraction of muscle fibres, and some waste heat. Use the words work heat. internal energy, conduction,emperature. heat capacity, and any other words ou like. to summarise the energy flow from chemicals in the cell through the body to the environment. Write about four sentences. (c) (3 marks) If the heat from metabolising the food was entirely retained within the hiker's body estimate her body temperature at the summit. State any additional assumptions you make Mammals are very good at maintaining constant core temperature. Most of the hiker's additional internal energy from climbing the mountain was not retained, and went into evaporating water from her skin. (d) (1 mark) When liquid water (sweat) evaporates from your skin, converting into water vapour, what temperature does that process happen at? (e) (3 marks) Use the data given on the plot to estimate how many litres of water she should drink during the climb to replace the lost fluids? NUTRITION INFORMATION (AVERAGE Servings per package-7 Serving size-40g (1 metric cupt) quantity % daily per serve quantity p intake per serving 7% with h per serving er cup skim 100g milk ENERGY PROTEIN FAT, TOTAL 620kJ 8.5 g 0.2 g

Answer 1

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5.5 6x35 T, 一天 1.23 2 T Samm fe 3500时! she ddssfpFea 15.90 . 5 anno ca 4500时!