Quiz - 5 - Diving Knowledge Workbook - Diving Physics

[Pedro Burrito]

From the Diving Physics Section of the PADI Diving Knowledge Workbook Version 2.02 © PADI 2009:

1.2 Question 3

When viewed underwater, objects tend to be magnified by a factor of about:

a. 10%

b. 33%

c. 50%

d. 74%​

I will post a daily question from my exams to help newer divers and to encourage more experienced divers to interact gracefully and helpfully with the newer divers.

Reminder - this is a post in the Basic Forum and it is a green zone. Please be nice and on topic.

Thank you for your patience while we try to give people something to discuss other than Covid-19 and/or Politics. I will post the answer covered by the spoiler tag later today.

 

[tursiops]

Cool. We get an extra 12h to argue about almost nothing.

 

[TMHeimer]

Let's see-- 4:3 and 33% larger. My wife did explain the math to me.

 

[Pedro Burrito]

Spoiler: Answer

b. 33%

 

[Dizzi Lizzi]

Is it weird that I feel I know the answer but check to make sure it's right before posting? Actually I thought it was 25% but picked 33 as it was the closest.

 

[TMHeimer]

Is it weird that I feel I know the answer but check to make sure it's right before posting? Actually I thought it was 25% but picked 33 as it was the closest.

Yeah that's what I thought-- as I said, my wife explained it to me. Oh, her name is Liz too....

 

[Angelo Farina]

Again, improper wording in the question. If the answer is the magnification factor, the correct answer should 133%, or 1.33, not 33%.
33% is the size INCREMENT, not the magnification FACTOR...
A factor is quantity which has to be multiplied for the real size, giving as result the apparent size.
So if the barracuda fish was 1m long, it will appear 1m x 1.33 = 1.33m long...
Instead an increment is quantity to be added to the real size, for providing the apparent size. It is expressed in percent of the real size.
So 1m + 0.33*1m = 1.33m