Science & Mathematics - 3 November 2006

A dike is holding back the sea from a town below sea level and it springs a leak 3.1m below the water surface. If the area of the hole in the dike is 0.012m^2, what force is needed to save the town? (The density of the sea water is 1025kg/m^3)

2006-11-03 07:48:59 · 3 answers · asked by brilliantdance12 1 in Physics

2006-11-03 07:46:04 · 6 answers · asked by ineedhelp 1 in Earth Sciences & Geology

I have seen this term "word problem" several times in the Math section. What does it mean exactly? It has nothing to do with words, right?

2006-11-03 07:45:41 · 4 answers · asked by Steiner 7 in Mathematics

2006-11-03 07:45:28 · 6 answers · asked by Looneygirl 2 in Earth Sciences & Geology

His first throw is clocked at 80 Km/hr and each succesive throw increases in velocity by 1.5% of the previous throw . He throws a ball 40 time in total
I know that the velocity of the baseball player can be determind by using the geometric sequence t=ar^n-1, but I don't know how to find out about rhe common ratio r
I calculated the ratio 3/2 but I am not sure is my answer is correct or not?

2006-11-03 07:42:22 · 3 answers · asked by shadab a 2 in Mathematics

wondering the amount a person would want in a sample and how much they would be willing to pay for it (dont worry about shipping)

2006-11-03 07:38:04 · 2 answers · asked by Anonymous in Chemistry

2006-11-03 07:34:41 · 3 answers · asked by Anonymous in Mathematics

2006-11-03 07:34:29 · 2 answers · asked by Anonymous in Mathematics

2006-11-03 07:34:05 · 2 answers · asked by Anonymous in Mathematics

2006-11-03 07:30:42 · 3 answers · asked by Pluralgirl 1 in Mathematics

2006-11-03 07:29:48 · 2 answers · asked by big daddy 1 in Astronomy & Space

sin beta = 12/13 , 90° < beta < 180°

tan beta = 3/4 , sin beta < 0

i don't understand the question, am i solving for beta and if so, how? thanks for the help.

2006-11-03 07:28:43 · 2 answers · asked by shih rips 6 in Mathematics

2006-11-03 07:28:10 · 4 answers · asked by Malet 1 in Chemistry

A freight train has a mass of 1.6 107 kg. If the locomotive can exert a constant pull of 8.5 105 N, how long does it take to increase the speed of the train from rest to 70 km/h?

2006-11-03 07:28:09 · 3 answers · asked by Tennis2127 2 in Physics

Details of how to work the problem would be helpful too please.

2006-11-03 07:26:35 · 13 answers · asked by m 3 in Mathematics

12s10 12s12

B.
5s7

C.
1

D.
none of these

2006-11-03 07:24:51 · 2 answers · asked by Anonymous in Chemistry

Someone gave me an old microwave at work. Whenever I run it, it completely wipes out the signal between my XM satellite radio receiver and my FM radio tuner, which I use to play the satellite radio music on. Is this a hazard to me?

2006-11-03 07:24:09 · 8 answers · asked by galacticsleigh 4 in Engineering

A national placement test has a normal distribution with a mean of 500 and a standard deviation of 100.

a) Find the z-score of 360. (-1.4)

b) Find the probability that a randomly selected student scores less than 640. (0.9192)

c) Find the probability that a randomly selected student scores more than 420. (0.2119)

d) Find the probability that a randomly selected student scores between 400 and 650. (0.7073)

e) Find the 90th percentile of the distribution (630)

2006-11-03 07:23:57 · 1 answers · asked by Connie S 1 in Mathematics

2006-11-03 07:23:14 · 15 answers · asked by Perm 1 in Geography

2006-11-03 07:22:26 · 2 answers · asked by Perfection 4 in Engineering

A maths homework problem...

Imagine a snooker table marked out with squares... if the table is 4x5 and you roll a ball from the bottom left pocket at 45 degrees...if the ball keeps rolling, bouncing off the sides at 45 degree angles, can you predict which pocket it will fall into? We've worked out that it will take [(width + height) + 1] bounces to fall into ONE of the pockets, but we're trying to figure out if there's a formula to predict WHICH pocket the ball will fall into.

The formula needs to work for any size of snooker table. Assume the ball always starts from the bottom left pocket.

Any ideas?

2006-11-03 07:22:26 · 2 answers · asked by Matt H 1 in Mathematics

hydrogen gas has been suggested as a clean fuel because it produces only water vapor when it burns. if the reaction has a 98.8% yield, what mass of hydrogen forms 85.0 kg of water?

2006-11-03 07:21:14 · 3 answers · asked by azncrazygurl520 1 in Chemistry

2006-11-03 07:17:14 · 13 answers · asked by thiskidthattheylove 2 in Physics

2006-11-03 07:17:04 · 6 answers · asked by Mr. Owl 3 in Astronomy & Space

2006-11-03 07:16:36 · 1 answers · asked by Cheesey E 1 in Engineering

I'm thinking about learning to use the program AutoCad. It's looks somewhat difficult to learn, the book for beginner is about 1,500 pages. I haven't even counted the workbook and references. Anyhow, it will be learned if AutoCad is proved useful.

To all of the AutoCad users out there, do you think it's a good program to learn if I am the type of person who loves to customize things and or invent something?

For example, I would like to build a desk but lack the skill of a handyman. Don’t want to buy the desk because I dislike the designs. I would like to use AutoCad to create a blueprint of the designs and then send it off to a company that will help me cut, sand, and paint all of the materials for me and then all I would need to do is put it together.

Will AutoCad help me do this? If I am wrong, then what is AutoCad use for? Please help.

2006-11-03 07:15:31 · 8 answers · asked by Inquisit 2 in Engineering

4.Find the perimeter of this solid. (Area of rectangle = length × width the sides are 2x,2 3x, 3x
P = 9x and A = 11x2

B.
P = 13x and A = 12x2

C.
P = 14x and A = 11x2

D.
none of these

2006-11-03 07:14:54 · 3 answers · asked by Anonymous in Mathematics

2006-11-03 07:13:51 · 2 answers · asked by reallyfedup 5 in Zoology

A high tech jet car speeds along the desert floor at a constant velocity of 180 miles/hr north.a) what is the net force on the jet car?
the jet car hits some sand which causes a drag force on the car of 5000 N to the south. The computer instantly compensates so the jet exerts a thrust force on the car of exactly 5000 N to the north at the same time the car hits the sand. The jet car now... choose ALL that apply:
slows down
remains at rest
maintains constant velocity
moves with constant non-zero velocity
speeds up
moves with a changing velocity
accelerates at a constant rate

Newton's first law states: When the ____ on an object is zero, the object will ____ constant ____.
Another way of saying this is that, if the total force on it equals zero, an object's ___ will also be zero.

Is it necessary to apply a force to keep an object going in a circle at constant speed?
Yes/No, because the ____ is changing/not changing.

2006-11-03 07:13:33 · 2 answers · asked by vintagex50s 2 in Physics

The random variable Z has a standard normal distribution.
a) What is the mean of Z?
b) What is the standard deviation of Z?
c) Find P( Z = 1.23)
d) Find P( Z < 1.23)
e) Find P( Z > -2.35)
f) Find P( -1.56 < Z < 2.74 )

2006-11-03 07:12:40 · 1 answers · asked by Connie S 1 in Mathematics