Physics - July 2007

How can I make a motion detector, from two cellphones, a floodlight, and a few other things? think third episode of Burn notice, where Michael had it rigged to set off the cell phone so he could tell when something was wrong. Anyone know how to make one?

2007-07-20 14:38:21 · 1 answers · asked by Anonymous

2007-07-20 13:09:26 · 2 answers · asked by Anonymous

If the engine(s) fail and autorotation is used to control the decent would the rotor have to change direction of rotation?

2007-07-20 12:31:37 · 4 answers · asked by Hopps T 1

Can a NATURAL HEAT SINK Remove Heat no matter how much heat?
Is it possible that no matter how much heat energy you have to deal with, it can still be dissipated or removed as long as there is an adequate 'heat sink'. Even if it takes the rest of the universe to do it. Can a 'natural heat sink' remove heat from Earth and send the heat out of the atmosphere.
In other words, if theres even more heat, just keep getting a "bigger" 'heat sink'?
In other words , dealing with the universe is there an infinite supply of material , ice or whatever, do deal with any heat transfer.

2007-07-20 11:11:38 · 3 answers · asked by MichelleMcD81 2

2007-07-20 10:58:13 · 4 answers · asked by kirsty1995 2

like spaghetti thrown at a wall. is it a function of suction or more like inertia? or is this a question i should be asking in the chemistry section?

2007-07-20 10:40:12 · 4 answers · asked by Anonymous

2007-07-20 10:21:35 · 5 answers · asked by Deepanshu93 1

Could you help me how can we use the dynamics energy of a high speed low pressure (atm) air, exits from a piping system equipped with a fan, without increasing the pressure on the exitting air and accordingly on the fan.

2007-07-20 09:32:08 · 2 answers · asked by saeed_x61 1

2007-07-20 09:17:09 · 2 answers · asked by JAMES 4

On the surface of a hypothetical planet X, the atmospheric pressure is 7.48 x 106 Pa, and the temperature is 575 K. On the earth's surface the atmospheric pressure is 1.00 x 105 Pa, while the surface temperature can reach 320 K. These data imply that the planet X has a "thicker" atmosphere at its surface than does the earth, which means that the number of molecules per unit volume (N/V) is greater on the surface of planet X than on the earth. Find the ratio (N/V)X/(N/V)Earth.

2007-07-20 08:52:11 · 3 answers · asked by lilbit_0203 1

2007-07-20 08:01:29 · 4 answers · asked by Mandél M 3

2007-07-20 07:37:08 · 6 answers · asked by Alexander 6

What happens with paradoxes in theory? Putting traveling back intime imposible aside. Im sure that you all have heard of the if you go back in time and kill your self then you never could be able to go back in time to kill yourself. So what would happen?

2007-07-20 06:56:15 · 7 answers · asked by schlynn2000 1

2007-07-20 06:41:55 · 13 answers · asked by hrishma r 1

ok i understand how we would be able to travel into the future but i have some questions... so if some one traveled at the speed of light and came back in an hour, they would be millions of years into the future right? well does that mean that we'd all die in an hour because nobody can live to be that old?

2007-07-20 06:32:29 · 18 answers · asked by sk8terdude 3

out of mass,time,energy space

2007-07-20 06:28:06 · 6 answers · asked by Anonymous

If it is possible to travel faster than time is it possible to travel faster than up/down or left/right? If you could travel faster that a particular dimention wouldnt that leave more energy to apply towards the dimentions you were traveling through?

2007-07-20 06:10:35 · 4 answers · asked by poppinoffalot 2

'When' the rapture happens, approximatly 20billion people will be brought out of the graves. They all will have to have bodies. It will take hundreds of billions of gallons of water, billions of pounds of carbon, iron, calcium etc. Atoms that used to be in their bodies will be in bodies that are alive then. How will we feed and water 20 billion extra people that first day? Where will they stand?
It is unacceptable to say...God will do it. God is a scientist. He always follows the laws of physics that he created.

2007-07-20 05:32:04 · 12 answers · asked by poppinoffalot 2

standing 80 ft away. He perfectly
knows that initail horizontal velocity
produced by his slingshot is 100 ft/s.


Because of sidewise gust of wind the ball
instead hit Mr. Thatcher's daughter Maggi
2 ft to the right of her father 1.0 second later.

What was the speed of the wind?

2007-07-20 05:28:33 · 2 answers · asked by Alexander 6

I mean the well known deep 'boing' like in the 'Das Boot' movie.
And why is it like that? Is the frequency somehow special or it does contain all frequencies or why is it such special?

2007-07-20 05:24:23 · 3 answers · asked by Anonymous

2007-07-20 04:24:38 · 8 answers · asked by Meremortal 1

2007-07-20 03:50:47 · 3 answers · asked by anrtech 1

I saw this article "Did stardust trigger snowball Earth?" originally from NATURE:
http://www.bioedonline.org/news/news.cfm?art=1559
"Our planet may have frozen over in the past as it drifted though giant dust clouds in space. The result of the dust-bath would have been an almost complete overcoat of ice for the world, according to a new theory." I thought that ice would burn up on atmosphere entry and burn up the planet, but someone said the massive ice was a "heat sink". Is there any way to calculate if say, it was a billion cubic miles of ice caving in on earth's atmosphere, if that would be enough of a "heat sink" to offset the friction of entry?

2007-07-20 02:20:08 · 3 answers · asked by MichelleMcD81 2

Please provide a theorum or something stating either way. thankyou

2007-07-20 02:08:27 · 6 answers · asked by rpalm82 2

how does the max wavelength that light can eject electrons from a meterial help me find the speed of electrons ejected when a ray with smaller wavelenght is incident?

2007-07-20 01:25:14 · 4 answers · asked by Anonymous

The age old question, I know & cliche, but what would happen? I told my friends that the gravity from all points would center on one location and crush anything there. is this true? What would happen?

2007-07-20 01:07:59 · 6 answers · asked by Casimir Effect 1

2007-07-20 00:52:16 · 14 answers · asked by skerferd 1

2007-07-20 00:23:45 · 9 answers · asked by Angellina4ever 1

2007-07-19 23:54:27 · 3 answers · asked by Vienna 3

a Ton of bricks, a Ton of feathers or a Ton of water

2007-07-19 23:45:10 · 26 answers · asked by hannah_detain 2