Physics - May 2007

I was thinking about how you could create a hover craft that would fly without wind or air and I was wondering why you can’t use magnets to repel off the earths own magnetic field. I figured that it’s maybe because the magnetic field of the earth does not generate a force greater then the gravity from its mass. Do I not know enough about the nature of magnets and magnetism? Is completely stupid?

Earths field is enought to push away solar flares (I know they're charged particles) and gravity increases in fourths as you move toward it (vice versa when moving away). Why not a super magnet to push off earths magnetic field, one that compensates for changes in polarity.

2007-05-12 13:55:31 · 5 answers · asked by Anonymous

1. if you have a free electron and a free proton between two oppositely charged plates, where will they go when they are released? How do the forcess on them compare? How do their accelerations compare? Which hits first?

2. The neighbors like to keep their 40.0W front porch light on at night to welcome visitors. If the light is on 6pm-7am and they pay 8.0cent per kwhr, how much does it cost to run the light for this amount of time each week?

2007-05-12 12:26:39 · 3 answers · asked by Rose 3

"Don't be fooled. Speed kills"
Do you agree with this slogan? Explain whether or not u agree with reference to a passenger not wearing a seatbelt, and ohysics laws/equations to substantiate your answer

2007-05-12 12:15:54 · 2 answers · asked by Sweet_b-yatch 1

2007-05-12 11:27:41 · 6 answers · asked by magnificientred 2

A cable is wrapped around a pulley in the shape of a solid cylinder(1/2mR^2) with rotational inertia I=0.250 kg-m^2 and radius R= 0.500m. The cylinder rotates without friction. The free end of the cable is connected to a block of mass m=1.0 kg on a rough inclined plane. This block is released from rest and slides down the incline to the bottom through vertical distance h=3.0m. During the motion, the plane exerts a frictional force on the block. At the bottom, the linear speed of the block is v=4.0 m/s.

a.) Use conservation of energy to compute the Heat (mu) that is generated during the motion.

please explain this one to me....

2007-05-12 11:16:22 · 1 answers · asked by biscuits 2

When I explained that I'm not a Mathematician (Physicist), but rather much closer to a Biologist, he seemed to gloat and assume he won something special.

Biology only deals with living things people, and with things that are now dead. It does not deal with whether or not the universe is infinite, how it expands, whether its expanding, or anything else to do with the nature of the universe. THAT is a Physicists perview.

Would other Christians automatically think that they must be right just because the person you asked the question to does not have experience in the question you're asking?

No single scientist would be a specialist in every single field out there. A Biologist does not understand all the information in Chemistry, a Chemist does not understand all the information in Physics.

If you wish to know a question that deals specifically with science, wouldn't it be better to ask in the science section where the question could be answered properly?

2007-05-12 10:43:36 · 8 answers · asked by Anonymous

i know this is a simple question, but i need a very descriptive and detailed answer. if you could help me that would be great!, and if you have a good wevsite that will tell me the answer in detail, that would be even better, thanks everyone!

2007-05-12 10:31:19 · 8 answers · asked by Anonymous

2007-05-12 10:14:34 · 2 answers · asked by London 5

when a straw is seen in the air ( as you see it normally, outside of water or liquid) it seems normal because light travelling from the straw is at normal speed . but when placed in water the speed of light travelling in water is decreased because water is denser than air

2007-05-12 10:13:29 · 6 answers · asked by Anonymous

2007-05-12 09:32:48 · 1 answers · asked by Random G 3

have only certain amounts of energy?

i dont know the answer...im a freshman taking physics and this is one of my hw questions....i cant find the answer in my book...

2007-05-12 09:22:33 · 2 answers · asked by xSoDaPoPx 1

how are objects magnified under water? is it due to the refraction of the visible light waves?
i need more of an explanation, and a good website or two, please help me!

2007-05-12 08:59:31 · 2 answers · asked by Anonymous

Put them in order from fastes transfer of heat to slowest transfer of heat

2007-05-12 08:50:06 · 7 answers · asked by Joanne M 2

Thanks for your help.

2007-05-12 08:41:51 · 2 answers · asked by Anonymous

i need a long descriptive answer, or a good website(s) that will tell me the answer

2007-05-12 07:40:16 · 3 answers · asked by Anonymous

at voltage gradients less than ionizing (30kv/cm), and with dry air, is there an agreed upon resistance (or maybe called resistivity) of air, ie ohms/meter? Does the concept make sense, ie since these concepts are statistical properties of molecular phenomena, at sufficiently low values ideas like temperature, etc become meaningless since there is not a large enough population for statistics to apply. thus, is there an accepted resistivity of air, can you tell me its value or point to a source?

2007-05-12 07:01:53 · 5 answers · asked by Richard K 3

2007-05-12 06:05:19 · 2 answers · asked by aleric 2

If our sun is powered by hydrogen where dose it come from ? There must be a finite supply of hydrogen for use as fuel. It would seem to me that the supply would be quickly exhaused. Yet the sun is billions of years old. Where dose the hydrogen come from to sustain the continued fusion reaction within the sun.

2007-05-12 05:40:05 · 12 answers · asked by kris_mccraw 2

Was the Jet Fuel and fire concentreated only on one small area of the buildings on 9/11?

2007-05-12 04:55:55 · 3 answers · asked by Mr. USA U 2

For my physics final we got a review sheet with statements on it. The statements are either true or false & we have to decide. Anybody out there who understands physics, could you please check the one's below and explain the others I'm unsure of?
Thank you SO much!

1.As a ball falls freely, the distance it falls each second is the same. (False)
2.The combination of all the forces that act on an object is called the net force (True)
3. The acceleration of an object is inversely proportional to the net force acting on the object (False)
4.The spped of an object dropped in air will continue to increase w/o limit until it strikes the ground(False)
5.If a bicycle and a parked car have a head on collision, the force of impact is greater on the bicycle (False)
6.A single vector can be replaced by two vectors in the X and Y directions. These X and Y vectors are called the resultant of the original vector
7. The force due to gravity acting on object is called the mass of the object.

2007-05-12 04:52:55 · 5 answers · asked by Anonymous

2007-05-12 04:31:12 · 1 answers · asked by Anonymous

2007-05-12 03:57:53 · 7 answers · asked by shiva dude 1

Can someone help me here if speed=ditsance traveled in a given amount of time then wouldnt the speed of light be expotential because it travels sphericaly from its point of origin and if that were true shouldnt Einsteins special theroy of relativity be energy = mass times the spherical velocity of light instead of square maybe I am just really confused is it total distance travled or distance between point a and point b only??? billy buttface please no answer

2007-05-12 03:51:28 · 6 answers · asked by Anonymous

If you are walking at constant velocity of 5 km/h and a car passed you by at the speed of 20 km/h from behind, what is the car's velocity from your viewpoint? i also want 2 know why?

2007-05-12 03:45:05 · 5 answers · asked by Varun N 1

Please help with the following exercise:

Given 2 resistors in series R1=10 ohms, R2= 30 ohms, determine the current flowing through the resistors and the voltage across each resistor, if the potential difference across the wire is V=12V.

This is how I solved it:

The total resistance Req= R1+R2= 40 ohms

R = V / i
i = V/R = 0.3 A

V(R1) = -R1*i = -10*0.3= -3V
V(R2) = -R2*i = -30*0.3= -9V

Is it correct? Can the voltage be negative? Please help.

Thank you.

2007-05-12 03:36:19 · 6 answers · asked by deluca.claudia 1

I’ve a standard energy saving light bulb in a room where I keep my PC, there are no windows in the room, but I’ve noticed the light bulb glows every 30 seconds when turned off? At first I thought it was a reflection from a LED on one of the items of computer gear, so I turned everything off, still happens? No mobile phones or wi-fi / Bluetooth devices / known transmitters in house, so what is making this bulb glow?

2007-05-12 03:29:38 · 11 answers · asked by Avon 7

I took a physics class that had a unit on optics, and I remember the instructor saying that what you see when you look in the mirror is a distortion, and that your face is actually more asymmetrical than it appears to you in the mirror. I just saw this guy's question, and I tried to answer it but realized I've forgotten everything I learned in that class.

http://answers.yahoo.com/question/index;_ylt=Ao83RbAktNRDJ1ZLGRW5mfkSxgt.?qid=20070511201556AAh7g5N

What causes that distortion, and are photographic images distortions too? Which is less distortive?

2007-05-12 03:10:10 · 8 answers · asked by dannygirl 3

Hi, I need help with the following exercise:

We have a square circuit, with 4 capacitors, 1 on each side of the square, all with the same capacitance C. Calculate the total capacitance of the system of capacitors between the two diagonally opposite corners of the square, A and B.

This is how I solved it, could you tell me if it's right?

A ) 2 capacitors (from A to B ): they are in series
B ) 2 capacitors (from B to A): they are in series

A )1/Ceq = 1/C1 + 1/C2= 2/C --> A-Ceq=C/2
B )1/Ceq = 1/C3 + 1/C4= 2/C --> B-Ceq=C/2

Now A-Ceq and B-Ceq are in a parallel configuration:

C) Ceq = C/2 + C/2 = C

The total capacitance is equal to C?

Thank you.

2007-05-12 02:57:53 · 3 answers · asked by deluca.claudia 1

Does this mean:
amplitude^2 = probability
or
Sqrt(amplitude)=probability

2007-05-12 02:52:03 · 2 answers · asked by muhammaddarwish 2

2007-05-12 02:50:19 · 6 answers · asked by BRIAN 2