Physics - June 2007

A curve of radius 125 m is banked at an angle of 22°. At what speed can it be negotiated under icy conditions where friction is negligible?

2007-06-08 15:08:50 · 5 answers · asked by Kat 1

how can I resonate a coil of wire at 10Mhz or any other given frequency.
I want to use it in the wireless transfer of energy for my science fair project.
Iam in 11th year. What do you think. Is it difficult for me?

2007-06-08 15:01:00 · 2 answers · asked by behroz ahmed ali 3

Calculate the 3rd harmonic frequency of a standing wave on a guitar string with a length of 1.20 m and a wave speed of 352 m/s. Give answer in Hz. (b) Calculate the fundamental frequency of this overtone. Give answer in Hz.

2007-06-08 14:52:55 · 4 answers · asked by Anonymous

In simple terms, current flow is the movement of electrons along a conductor. Electrons are small, and even a small current involves millions of electrons.

Now consider inserting a resistance into a conductor. Fewer electrons flow. As the resistance increases, fewer electrons flow. Now picture a current flow equivalent to 1 electron per second.

Whatever that current may be (I'm curious as to what this value would be), if the resistance was increased further, would all current flow stop - as you cannot have a current flow of (say) half an electron. Or can you? Say one electron every 2 seconds? Is there a theoretical minimum, and if so, what is it?

Also, can it be shown in practice? If so, how?

2007-06-08 14:27:26 · 6 answers · asked by Anonymous

I'm a grade 11 physics student studying for an upcoming test, can't find a proper definition anywhere, could you please help?

2007-06-08 14:23:20 · 8 answers · asked by Anonymous

Thermodynamics states that it is almost impossible for all the gas particles in a room to gather themselves into one side of the room, as this would decrease the number of microstates (by 2^n), violating the second law of thermodynamics(spontaneous reduction of entropy cannot occur).
What explanation is given for gravity which can attract particles to one another in large scales, reducing microstates? i.e. a massive cloud of H2 condensing under gravity to form a star? What happens to the entropy?

2007-06-08 14:16:40 · 7 answers · asked by Anonymous

what happens between earth and apple when apple is falling towards the center of earth? what is difference between gravitational force and magnetic force? what happens between two magnets when they repeal and attracts? is there any similarities between these two forces?

2007-06-08 14:10:21 · 14 answers · asked by mama v 1

A speeding car is pulling away from a police car. The police car is moving at 30 m/s. The radar gun in the police car emits an electromagnetic wave with a frequency of 20.0 x 109 Hz. The wave reflects from the speeding car and returns to the police car where the frequency is measured to be 475 Hz less than what was emitted. The speed of sound is 343 m/s. How fast is the speeding car going?

This is the question I'm working on. I know that I first have to find the frequency when the wave hits the speeding car, however I'm not sure how to do that. I can't seem to find a way to figure out the frequency when I do not have the speed of the car. What equation should I use to find the frequency? Thanks in advance for any help.

2007-06-08 13:57:02 · 4 answers · asked by Darkshine 2

2007-06-08 13:20:03 · 5 answers · asked by Anonymous

2007-06-08 13:00:02 · 9 answers · asked by Anonymous

2007-06-08 12:52:29 · 9 answers · asked by Lorenzo de' Medici 1

if we model the air resistance on a falling person as being proportional to the square of that person's speed, in certain circumstanjces the proportionality constant between the air resistance and the square of the speed is equal to 0.100 kg/m. A) What would the terminal velocity of a 72 kg person? B) What would be the air resistance when the person's speed is half the terminal velocity?

2007-06-08 12:48:49 · 4 answers · asked by physicsdum 1

Say, for arguements sake, the sun simply disappeared, and empty space was all that was left (ie no remaining mass), at what point would the earth fly off at a tangent to its orbit? 8 minutes later or instantaneously?

2007-06-08 12:30:00 · 14 answers · asked by Anonymous

2007-06-08 11:56:45 · 6 answers · asked by Anonymous

He does not move, his displacement is zero.
The work must be therefore zero too. Useless pool.

2007-06-08 11:46:14 · 2 answers · asked by Alexander 6

Aim remains the same. Ignore air resistance.

2007-06-08 11:33:25 · 10 answers · asked by Alexander 6

I`ve seen a very interesting video about how invisibility cloaks are made. Do you think you can make one at home. It would be like Harry Potter http://www.metacafe.com/watch/638074/make_an_invisibility_cloak/

2007-06-08 10:34:05 · 12 answers · asked by Tudor 1

If Captain Kittinger jumped from a little higher he would've created a sonic boom!

Does it hurt, or would the density be low enough to cause the sonic boom's energy per cubic meter level to be negligable?

2007-06-08 09:37:27 · 16 answers · asked by anonymous 4

we all know that if you put two magnets together they stick, but if you turn one around they wont. Why cant we use powerful magnets to make turbines turn and create power that is very safe, cheap clean and endless.

2007-06-08 09:20:00 · 6 answers · asked by Anonymous

If a charged paticle is moving with a constant velocity in some region of space could there be a possibility that a magnetic field could be present plz explain

2007-06-08 07:01:46 · 7 answers · asked by rohandon c 1

ok ive been thinking about this for a while...now im only 15 so im not an expert on anything and dont claim to be, but i love science. one of the most interesting subjects in my opinion are black holes. well you know hawking's information paradox thing right? that everything sucked into a black hole simply dissapears when the black hole dies? and everyone argued that such a theory is stupid because no matter what information can never be lost right? so apparently it goes somewhere according to them.

well i was thinking, if no matter what information can never be lost then what about when people die? like say an old man discovered something about the universe that no one knew before him but died before he got the chance to tell anybody. wouldnt that mean that that information was lost? especially because as humans, death is the end of the road and there is no way for us to know whats on the other side?

cant that mean then that hawking could be right??

2007-06-08 07:00:56 · 10 answers · asked by bandicoot 3

2007-06-08 06:47:16 · 3 answers · asked by yashi m 3

why does fusion generate more energy than fision

2007-06-08 06:38:28 · 8 answers · asked by drewsgotblues 1

A rock thrown at 45 degrees travels along parabolic
trajectory for longest possible distance.
For example, if initial velocity is 20 m/s, the rock lands
40 meters away if thrown at 45 degrees.

According to Kepler laws, however, the trajectory of the
rock muct be ellipse, with one focus at the center of the
earth. Where is the second focus of this ellipse?

2007-06-08 06:20:23 · 4 answers · asked by Alexander 6

The scientists made a convention that triple point of Gallium has absolute temperatere 300 Nivlek.

I have glass container which contains cryptonite apparently at tripple point.

How can I establish absolute temperature of cryptonite?

2007-06-08 06:09:09 · 6 answers · asked by Alexander 6

Theres two tug boats, the magnitude of the resultant vector is 6000lbs. And each towline makes an angle of theta for both lines along a single axis.

What is the tension, if theta = 20 degrees?
And what is the Tension equation in respect of theta being a variable?
I guess if i know the equation i can find the 20degrees.

2007-06-08 05:46:11 · 2 answers · asked by Catcher InTheRye 2

A simple mercury barometer indicates a reading of 760 mmHg when used on Earth to measure an atmospheric pressure of 1.0x10^5 Pa. The pressure of air in a space orbit about the Earth is 0.9x10^5 Pa.
Explain why the barometer cannot be used to measure this pressure and state what would happen if an attempt were made to do so.

2007-06-08 05:10:21 · 7 answers · asked by Anonymous

Hi! physics question! 10 points If ya' can awnser! How many joules of energy does a federal frigate (such as the U.S.S. Wabash http://www.unionnavy.org/img48.gif) have the potential to create?
The engine generates about 1000 horsepower and it is armed with 54 nine inch guns. If she was under full steam, the galley stove was on, and she fired all her guns at once, approximately how many joules of energy would this create?

2007-06-08 04:53:57 · 5 answers · asked by Anonymous

then how can one party win?
This is not a riddle, I have a conceptual doubt in Physics. It's based on the laws of motion.

2007-06-08 04:48:40 · 7 answers · asked by Malfoy vs Potter 5

A swimmer shines a beam of light in water up toward the surface. It strikes the air-water interface at 30°. At what angle will it emerge into the air?
_____ ° (to the surface)


** Refraction and Reflection Unit - Physics

2007-06-08 04:45:46 · 3 answers · asked by Khoi 1