PADI IDC Theory: Physics

It's easier than you think

PADI IDC Theory: Physics. PADI Course Director Steve Prior explains why it’s easier than you think!
Lots of Practice Questions, Videos and Presentations
The Online course makes sure that nothing is left out. 
Steve takes you through every subject in an easy to follow process. 
Lot’s of questions, quizzes, Mock Exams to check your progress. 

PADI IDC Theory: Physics - Pressures Underwater

The Basics

Calculating pressures in sea water is essential. Without this knowledge you’ll really struggle with some PADI Physics exam questions, ones like where they ask you what size a balloon will be when you take it to 30 metres / 99 feet.
The good news is that it’s easy! 

How it's done

For every 10 metres or 33 feet, the water (or gauge) pressure changes by 1 atm.
The total pressure at depth includes both gauge and atmospheric pressure. 
So, pressure at 10 metres or 33 feet = 1 atm for the gauge pressure, and 1 atm = 2 atm.  

This might help

Metric
For every one metre in sea water, pressure changes by 0.1 atm. Example: at 23 metres pressure is: 23 X 0.1 = 2.3 atm for gauge, +1 = 3.3 for absolute. 
Imperial
For every foot of sea water, pressure changes by 0.0303 atm. Example at 76 feet pressure is 76 X 0.0303 = 2.3 atm for gauge + 1 = 3.3 for absolute
Fresh Water
In fresh water, it’s much the same, but for metric use 0.097 for every metre, and in imperial use 0.0294 for every foot.Effe

Test yourself with these PADI Exam questions on PHYSICS

These videos are from our online Preparation Course. Please don’t over complicate Physics. It’s easier than you think. More information here: PADI IDC Theory Preparation Course  Or sign up for a course here: 

PADI IDC Theory: Physics - Effects of Pressure

The Basics

These questions usually make up around 40% to 50% of all PADI IDC Physics exams. Anything to do with  changes at depth: Balloons, Breathing rate, Density, Partial Pressure of gasses, How much air needs to be pumped from the surface etc.  

How it's done

Watch the video to get a really good tip on how to work these out!  
As you get deeper, some things get smaller (e.g volumes)  and some things get larger (e.g.density, breathing rates) 
First, work out whether the answer will be larger or smaller. That will tell you whether you’ll multiply or divide. 

These videos are from our online Preparation Course. Please don’t over complicate Physics. It’s easier than you think. More information here: PADI IDC Theory Preparation Course  Or sign up for a course here: 

PADI IDC Physics - Displacement

The Basics

his subject is much simpler than some instructors make it out to be. 
Take a look at the video with an open mind and you’ll be surprised at how easy it is.  

How it's done

Metric
In fresh water, it’s often as simple as taking one number (displaced water) from another (weight). 
In salt water, first divide the weight by 1.03, and then go ahead as with fresh.
Imperial
Multiply the cubic feet of displaced water by 62.4 in fresh water, or 64 in sea water, then deduct that number from the weight of the object. Divide that number by either 62.4 or 64 depending on fresh or sea to get the answer in cubic feet.

Test yourself with these PADI Exam questions on PHYSICS

PADI IDC and IE Preparation Online Course

Videos and Presentations
The IDC Theory Preparation  Course has a lot more videos, presentations and guidance to help you prepare. 
Keep it simple!
Despite the course being friendly and simple, there is nothing missing. PADI Dive Theory, and PADI Standards are all fully covered. You’ll find no nasty surprises on your PADI IDC. 
Over 700 Questions
After each lesson, there are quiz questions where you can test your knowledge. In addition there are 10 mock theory exams. All with the same format and content to the final PADI exams that you’ll find on your course. 
More information IDC Theory Preparation Course    or Sign up for the IDC Theory Preparation Course here.

IDC Theory Preparation Course

Test yourself with these PADI Exam questions on PHYSICS

These videos are from our online Preparation Course. Please don’t over complicate Physics. It’s easier than you think. More information here: PADI IDC Theory Preparation Course  Or sign up for a course here: