College Physics Problem 1.29


How many heartbeats are there in a lifetime?


Solution:

The general assumptions:

  • There is 1 heartbeat in 1 second
  • In half a lifetime, there are 109 seconds.

Therefore, in a lifetime, the number of heartbeats is

\displaystyle 1\:lifetime=\left(1\:lifetime\right)\left(\frac{10^9\:sec}{0.5\:lifetime}\right)\left(\frac{1\:heartbeat}{1\:sec}\right) 

\displaystyle 1\:lifetime=2\times 10^9\:heartbeats         ☚