College

Des Linden won the Boston Marathon in 2018, becoming the first American woman to win since 1985. The harsh conditions (heavy rain and a headwind) led to a winning time of 2 hours, 39 minutes, and 54 seconds. If she weighed 99 pounds, her average heart rate during the race was 170 beats per minute, and her heart pumped 2.5 mLs of blood per kg of body mass per beat, how much blood did her heart pump during the race?

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Note: You may want to include the conversion of pounds to kilograms and ensure students understand the necessary calculations to answer the question.

Answer :

Answer:

3050.6 Litre .

Explanation:

Total time of heart beat = Total time of race = 2 hrs , 39 minutes and 54 seconds

= 2 x 60 + 39 + 54/60 min

= 120 + 39 + .9 min

= 159.9 min

rate of heart beat = 170 per min

Total no of heart beat during race = 170 x 159.9

volume of blood per kg per beat = 2.5 mL per kg of weight

body weight = 99 pounds = .4535 x 99 kg = 44.89 kg

volume of blood per beat = 2.5 mL x 44.89 mL

= 112.225 mL .

Total required volume of blood = 112.225 x 170 x 159.9 mL

= 3050612 mL

= 3050.6 L.

Final answer:

To calculate the total blood volume pumped by Des Linden's heart during the 2018 Boston Marathon, we determine her body mass in kg, multiply it by the volume of blood pumped per kg per beat, and then multiply by the total number of beats during the race, resulting in approximately 3058 liters of blood pumped.

Explanation:

In 2018, Des Linden won the Boston Marathon, with a noted heart rate and blood-pumping rate. To calculate how much blood her heart pumped during the marathon, use the following information:

Des Linden's weight: 99 pounds (which is approximately 45 kg, since 1 pound equals 0.453592 kg).

Average heart rate during the race: 170 beats per minute.

The volume of blood pumped per beat per kg of body mass: 2.5 mL.

Duration of the race: 2 hours, 39 minutes, and 54 seconds (which converts to 9594 seconds).

First, convert Des Linden's weight to kilograms:

99 pounds × 0.453592 kg/lb = 44.91 kg (approximately 45 kg).

Next, calculate the total volume of blood pumped during the marathon:

Volume per beat = Body mass in kg × Volume of blood pumped per kg per beat = 45 kg × 2.5 mL/kg = 112.5 mL per beat.

Then, calculate the total beats over the race duration:

Total beats = Average heart rate × Race duration in minutes = 170 beats/minute × 159.9 minutes = 27183 beats (approximately).

Finally, calculate the total volume of blood pumped during the race:

Total blood volume pumped = Volume per beat × Total beats = 112.5 mL/beat × 27183 beats = 3058087.5 mL = 3058 L (approximately).

Therefore, Des Linden's heart pumped approximately 3058 liters of blood during the marathon.