# submergency

### calculate wave length from height and period?

i have data on significant wave height and mean wave period. i need to find out wave length (λ lambda). i know that wave length equals wave speed (c) times wave period. i also know that wave speed equals the square root of ((gravity*wave length)/2*pi) or c=sqrt((9.8*λ)/(2*pi())).

can somebody help me solve this for wave length (λ) please?

4 AnswersMathematics1 decade ago### Hydraulic pressure at the bottom of a cone?

Suppose a cone has a top diameter of 10 meters and is 10 meters high. Suppose you filled it to the brim with fresh water. What would be the pressure of the water at the bottom? Would it be any different to the pressure of water at the bottom of a 10 meter diameter cylinder?

3 AnswersPhysics1 decade ago### Where can i find out about the energy in light at particular wavelengths?

Is it true that "Light carries about 350 Kcal/mole at 550 nm"?

3 AnswersPhysics1 decade ago### Surface area of a square tent with pyramid top?

I am trying to calculate the surface area of a tent. The tent is square, with a square pyramid on top and has no floor. The sides of the tent are 20 ft. The height of the vertical wall is 14 ft. The height overall is 20 ft, so the vertical height from the base of the pyramid to the apex is 6 ft.

In the following, sl=length of a side=20; wh=wall height=14; pl=perimeter length=80; ph=pyramid height=6.

sh is the slant height (hypotenuse) along the bisector of a face of the pyramid.

To calculate the surface area I added the area of the walls to the top surface area of the pyramid:

aw=pl*wh

sh=sqrt(((sl/2)^2) + (ph^2))

at=(pl*sh)/2

sa=aw + at

=(pl*wh) + ((pl*(sqrt(((sl/2)^2) + (ph^2))))/2)

=7932.381 ft^2

In a previous question, I was given a simplification of my method as:

surface =pl*(wh + sqrt((sl/2)^2+ph^2)))

I get 224 using this formula, but the correct answer is 7932.381.

Can somebody please help me work out where I am going wrong?

1 AnswerMathematics1 decade ago### Volume and surface area of a square tent with pyramid top?

I am trying to calculate the volume and the surface area of a tent. The tent is square, with a square pyramid on top and has no floor. The sides of the tent are 20 ft. The height of the vertical wall is 14 ft. The height overall is 20 ft, so the vertical height from the base of the pyramid to the apex is 6 ft.

In the following, sl=length of a side=20; wh=wall height=14; pl=perimeter length=80; ph=pyramid height=6.

sh is the slant height (hypotenuse) along the bisector of a face of the pyramid

To calculate the volume, I added the volume of the pyramid to the volume of the cube:

vc=sl^2*wh

vp=(1/3)*sl^2*ph

vp=vc+vp

=(sl^2*wh)+((1/3)*sl^2*ph)

=6400 ft^3

To calculate the surface area I added the area of the walls to the top surface area of the pyramid:

aw=pl*wh

sh=sqrt(((sl/2)^2)+(ph^2))

at=(pl*sh)/2

sa=aw+at

=(pl*wh)+((pl*(sqrt(((sl/2)^2)+(ph^2))))/2)

=7932.381 ft^2

Q: a) are the answers correct? b) is there a better method? c) can the formulas be simplified?

1 AnswerMathematics1 decade ago### Volume of a section of a sphere?

This is not homework, and I am trying to work out how generally to solve this problem as part of something I want to build, so explanations are very much appreciated. Here's the problem:

Take a sphere of radius say 30 meters.

Run a cylinder of radius say 18.541 meters right through its middle. Like the core of an apple. (Very big apple.)

What is the volume of the sphere minus the volume intersected by the cylinder? How much apple is left if the core is removed?

You might say, easy, calculate the volume of the cylinder and subtract it. But the cylinder has ends that have a radius of curvature equal to that of the sphere and you have to calculate the volume of those first.

Another approach might be to treat the portion remaining as a toroid and calculate its volume from its cross section area and circumference or something.

I'm stumped. Can some-one help pleeaase?

4 AnswersMathematics1 decade ago### Is it harder to blow a balloon up underwater?

Imagine you are underwater, sitting on the bottom not too far down - say 10 meters / 30 feet or so. You are presumably breathing using SCUBA gear. Forget about the inconvenience of the mouthpiece or whatever. I am interested in pressure, how much work you have to do to push your breath into the balloon. Do you have to breath / push harder, push air at a higher pressure, into the balloon to inflate it than if you were at the surface?

10 AnswersPhysics1 decade ago### Please help me to solve this equation for d: rl=sqrt(rc^2-(rc-d)^2)?

This is a formula for calculating the radius of a sphere at a particular level. rl = radius at level, rc = radius of curvature, d = distance to level from center of sphere. see http://www.monolithic.com/construction/formulas.pd...

3 AnswersMathematics1 decade ago