Question

How many liters of blood does a heartbeat in 1 year? In 70 years? Write answer in scientific notation. There are boxes at the bottom to select the 2 answers.

Answer 1

To answer this question we need to know how many liters of blood are pumped in a minute; we know the amount the heart pumps per heartbeat and how many times the heart beats in a minute, multyplying this quantities will lead to the amount of blood the heart pumps each minute:

`(7*10^(-2))(72)=5.04`

Hence the heart pumps, in average, 5.04 liters per minute.

Now we need to determine how many minutes a year have. We know each year has 365 days, each day has 24 hours and each hour has 60 minutes, then a year has:

`365\cdot24\cdot60=525600`

Hence, each year has 525,600 minutes.

With this information we can determine how many liters are pumped in a year; we just multiply the number of minutes in a year by the amount pumped in a minute:

`5.04\cdot525600=2.65*10^6`

Therefore, in 1 year, the heart pumps

`2.65*10^6`

liters of blood.

To determine how many liters the heart pumps in 70 years we multiply the amount we just found by 70:

`2.65*10^6\cdot70=1.85*10^8`

Therefore, in 70 years, the heart pumps

`1.85*10^8`

liters of blood.