# Problem: The lower end of a long plastic straw is immersed below the surface of the water in a plastic cup. An average person sucking on the upper end of the straw can pull water into the straw to a vertical height of 1.1 m above the surface of the water in the cup. What is the lowest gauge pressure that the average person can achieve inside his lungs?

###### FREE Expert Solution

Gauge pressure is given by:

$\overline{){\mathbf{P}}{\mathbf{=}}{\mathbf{\rho }}{\mathbf{g}}{\mathbf{h}}}$, where ρ is the density of water, g is the acceleration due to gravity, and h is the vertical height.

Lowest pressure achievable inside the lungs:

$\overline{){{\mathbf{P}}}_{\mathbf{l}\mathbf{u}\mathbf{n}\mathbf{g}\mathbf{s}}{\mathbf{=}}{{\mathbf{P}}}_{{\mathbf{0}}}{\mathbf{+}}{\mathbf{P}}}$, where P0 is atmospheric pressure.

###### Problem Details

The lower end of a long plastic straw is immersed below the surface of the water in a plastic cup. An average person sucking on the upper end of the straw can pull water into the straw to a vertical height of 1.1 m above the surface of the water in the cup. What is the lowest gauge pressure that the average person can achieve inside his lungs?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Intro to Pressure concept. You can view video lessons to learn Intro to Pressure Or if you need more Intro to Pressure practice, you can also practice Intro to Pressure practice problems .

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Pau's class at UCLA.