Question

Heart beats 2,320 times during 20 minutes of rowing. While resting the heart is beating 16 times in 15 seconds. What is the difference between the heart rate when it is rowing versus resting?

Answer 1

0.87 beats per second

Explanation:

We are given that the heart beats 2,320 times during 20 minutes of rowing.

So heart rate while rowing =
`(2320)/(20 * 60) =(2320)/(1200)` = 1.93 beats / second

And while resting, the heart beats 16 times in 15 seconds.

So heart rate while resting =
`(16)/(15)` = 1.07 beats / second

Therefore, the difference between the two hearts rates =
`1.93-1.07` = 0.87 beats per second

Answer 2

Answer: 0.87 times per second (Or 52.2 times per minute)

Explanation:

You need to make the conversion from minutes to seconds.

Remember that 1 minute has 60 seconds. Then 20 minutes to seconds is:

`(20minutes)((60seconds)/(1minute))=1,200seconds`

Find the number of times the heart beats in 1 second when it is rowing:

`x_1=((2,320times))/(1,200seconds)=1.93\ times\ per\ second`

Find the number of times the heart beats in 1 second when it is resting:

`x_2=((16times))/(15seconds)=1.06\ times\ per\ second`

Then the difference is:

`difference=(1.93-1.06)\ times\ per\ second\\difference=0.87\ times\ per\ second`

(Or 52.2 times per minute)