Question
How many grams of carbohydrate does a person of mass 75 kg need to metabolize to climb five flights of stairs (15 m height increase)? Each gram of carbohydrate provides 17.6 kJ of energy. Assume 10.0% efficiency—that is, 10.0% of the available chemical energy in the carbohydrate is converted to mechanical energy.
g
What happens to the other 90% of the energy?
Could someone show me how to do this please. Thanks. I have a hard time figuring it out.
g
What happens to the other 90% of the energy?
Could someone show me how to do this please. Thanks. I have a hard time figuring it out.
Answers
The person needs to do an amount of work of W = 75 kg * 15 m * 9.81 m/s^2 against gravity.
Per gram of carbohydrates, you have available 10% of 17.6 KJ to do mechanical work, so you need to divide W by 1.76 KJ to find the amount of carbohydrates needed in grams.
The other 90% converted to heat.
Per gram of carbohydrates, you have available 10% of 17.6 KJ to do mechanical work, so you need to divide W by 1.76 KJ to find the amount of carbohydrates needed in grams.
The other 90% converted to heat.