The student’s body is 22% percent efficient; that is, for every 22 J that are converted to mechanical energy, 100 J of chemical energy are expended, with 78 J going into thermal energy.

How much chemical energy is expended by the student during the climb? Answer in units of kJ.

ALLAN

To determine the amount of chemical energy expended by the student during the climb, we need to first determine the amount of mechanical energy converted. We know that for every 22 J of mechanical energy, 100 J of chemical energy are expended.

Let's assume that the amount of mechanical energy converted during the climb is 'x' J. Since we know that the efficiency is 22%, we can set up the following equation:

x J * (100 J/22 J) = x J * (4.54)

Now, we need to convert the result from joules (J) to kilojoules (kJ). To do this, divide the result by 1000:

(x J * 4.54) / 1000 = (x * 0.00454) kJ

Therefore, the amount of chemical energy expended by the student during the climb is 0.00454 * x kJ.

However, we don't have the specific value for 'x'. If you provide the value of mechanical energy converted during the climb, we can substitute it into the equation and calculate the amount of chemical energy expended in kilojoules.