calculating heart rate a level biology

Can someone help with this question plz

Calculate the heart rate of the dog in beats per minute

(edited 3 years ago)

Screenshot 2021-04-27 225320.jpg349.6KB

To work it out, you need to figure out how many 'waves' there are per unit time.

It looks like there are 3 waves in 1s (i think thats what the x axis is referring to), therefore 3 * 60 (to get it in minutes) = 180bpm

Reply 2

sara.m12

Original post by app_

I did that but I got the answer wrong. The answer was a decimal? 160.something

Reply 3

app_

Original post by sara.m12

I did that but I got the answer wrong. The answer was a decimal? 160.something

In that case maybe count how many lines there are between the 2 Q's and then work back from that.
That would mean there's 1 "beat" in x seconds, n then multiply up to get bpm.

I did it roughly n got something like 166.666....? ((idk if i counted all the lines tho))

Reply 4

Aeshakhan

Can someone properly explain this please I’m struggling with this question

Reply 5

2023 student

Original post by Aeshakhan

Can someone properly explain this please I’m struggling with this question

So am I, I don't understand it

Reply 6

mauriciofe

I did the calculation taking the point P as reference.
The first happened at 0.03s and the second at 0.39, therefore, the interval for a heartbeat is 0.36sec.
60 (seconds on a minute) / 0.36 = 166.6666...
You round it up to the closest whole number, which is 167 beats per minute.
I remember this question being on a past paper 1 2020 and on the mark scheme this is one of the acceptable answers.