Change the chapter
Question
One way to force air into an unconscious person’s lungs is to squeeze on a balloon appropriately connected to the subject. What force must you exert on the balloon with your hands to create a gauge pressure of 4.00 cm water, assuming you squeeze on an effective area of $50.0\textrm{ cm}^2$?
$1.96 \textrm{ N}$
Solution Video

# OpenStax College Physics for AP® Courses Solution, Chapter 11, Problem 70 (Problems & Exercises) (1:27)

Rating

No votes have been submitted yet.

Quiz Mode

Why is this button here? Quiz Mode is a chance to try solving the problem first on your own before viewing the solution. One of the following will probably happen:

1. You get the answer. Congratulations! It feels good! There might still be more to learn, and you might enjoy comparing your problem solving approach to the best practices demonstrated in the solution video.
2. You don't get the answer. This is OK! In fact it's awesome, despite the difficult feelings you might have about it. When you don't get the answer, your mind is ready for learning. Think about how much you really want the solution! Your mind will gobble it up when it sees it. Attempting the problem is like trying to assemble the pieces of a puzzle. If you don't get the answer, the gaps in the puzzle are questions that are ready and searching to be filled. This is an active process, where your mind is turned on - learning will happen!
If you wish to show the answer immediately without having to click "Reveal Answer", you may . Quiz Mode is disabled by default, but you can check the Enable Quiz Mode checkbox when editing your profile to re-enable it any time you want. College Physics Answers cares a lot about academic integrity. Quiz Mode is encouragement to use the solutions in a way that is most beneficial for your learning.

## Calculator Screenshots

Video Transcript
This is College Physics Answers with Shaun Dychko. When using a balloon to inflate a person's lungs, the pressure in the balloon is 4.00 centimeters of water— this is the gauge pressure, the pressure by which the pressure in the balloon exceeds atmospheric pressure— and the area over which a person's hand is touching the balloon is 50.0 square centimeters which we convert into meter squared by multiplying by 1 meter for every 100 centimeters twice that is 0.00500 square meters. So this pressure has a very unusual unit of cm H 2 O so we have to turn that into pascals and we'll do that by multiplying by the density of water times gravitational field strength times height because this is the gauge pressure of a column of fluid. And so we have the density of water is 1.000 times 10 to the 3 kilograms per cubic meter times 9.80 newtons per kilogram times the height converted into meters by multiplying by times 10 to the minus 2; this works out to 392 pascals. So then we return to this formula, pressure is force per area, and we solve for F by multiplying both sides by A. So F is P times A; 392 pascals times 0.00500 meter squared and that's 1.96 newtons has to be applied to the balloon.