climbers carry bottled oxygen when at very high altitudes. (a) Assuming that a mountain climber uses oxygen at twice the rate for climbing 116 stairs per minute (because of low air temperature and winds), calculate how many liters of oxygen a climber would need for 10.0 h of climbing. (These are liters at sea level.) Note that only 40% of the inhaled oxygen is utilized; the rest is exhaled. (b) How much useful work does the climber do if he and his equipment have a mass of 90.0 kg and he gains 1000 m of altitude? (c) What is his efficiency for the 10.0-h climb? Step-by-step solution Step 1 of 6 The formula to find the efficiency is, Here is the efficiency, is the output work and is the input work. Step 2 of 6 (a) The amount of oxygen required in liters is, Therefore, the amount of oxygen required is . Step 3 of 6 (b) The useful work done by the climber, Substitute for , for and for . Therefore, useful work done by the climber is . Step 4 of 6 (c) Use the formula for efficiency, Step 5 of 6 Step 6 of 6 Substitute for and for . Therefore, the efficiency is .

Step-by-step solution Step 1 of 6 The formula to find the efficiency is, Here is the efficiency, is the output work and is the input work.