Question

How many more bpm was his heart rate while racing than while resting?

Heart rate is described as the number of heart beats per minute. The normal human heart rate ranges from 60-100 beats per minute (bpm). Lance Armstrong (pictured above) had a resting heart rate of 32 beats per minute. While racing, his heart rate would increase to 1.6 beats per second. How many more bpm was his heart rate while racing than while resting?

Answer 1

`64 \ "bpm"`

Explanation:

Using dimensional analysis, we can convert `1.6 \ "bps"` to `"bpm"`.

We get:

`(1.6 \ "beats")/(color(red)cancelcolor(black)"second")*(60color(red)cancelcolor(black)"seconds")/("min")=96 \ "beats/min"`

So, the change is:

`Delta_"bpm"="bpm"_"new"-"bpm"_"old"`

`Delta_"bpm"=96 \ "bpm"-32 \ "bpm"`

`=64 \ "bpm"`