At a resting pulse rate of 81 beats per minute, the human heart typically pumps about 65 mL of blood per beat. Blood has a density of 1060 kg/m3. Circulating all of the blood in the body through the heart takes about 1 min for a person at rest. Required:a. How much blood is in the body? b. On average, what mass of blood does the heart pump with each heart beat?

5.265L/body ; 68.9×10³ kg / beat

Explanation:

Given the following :

Resting pulse rate = 81 beats / minute

Amount of blood pumped per beat = 65mL = (65 / 1000)L = 0.65L

Density of blood = 1060 kg/m^3

Circulation time = 1 minute for a person at rest

A.) How much blood is in the body?

Resting pulse rate × amount of blood pumped per beat * circulating time

(81 beat / min) × 0.65L/beat * 1minute / body = 5.265L / body

B.) b. On average, what mass of blood does the heart pump with each heart beat?

0.065L/beat * 1m³/1000L= 0.000065 m³ / beat

From density = mass / volume ;

Average mass = density * volume

= 1060kg/m³ * 0.000065 m³ / beat

= 0.0689kg / beat

= 68.9 × 10³ kg / beat