Physics - November 2007

how does it reduce noise pollution?

2007-11-27 04:56:28 · 2 answers · asked by Anonymous

2007-11-27 04:45:36 · 1 answers · asked by someone2841 3

A uniform plank of length 5.3 m and weight 218 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support (see the drawing). To what distance x can a person who weighs 446 N walk on the overhanging part of the plank before it just begins to tip?

2007-11-27 04:44:28 · 1 answers · asked by Anonymous

2007-11-27 04:22:08 · 4 answers · asked by Pascal 4

2007-11-27 03:58:16 · 12 answers · asked by BabieeHayley 1

2007-11-27 03:27:08 · 5 answers · asked by ??? 2

3. [P15-7] Oppositely charged parallel plates are separated by 5.33 mm. A potential difference of 600 V exists between the plates. (a) What is the magnitude of the electric field between the plates? (b) What is the magnitude of the force on an electron between the plates? (c) How much work must be done on the electron to move it to the negative plate if it is initially positioned 2.90 mm from the positive plate?



4. [A15-1b] Rub an inflated balloon with a piece of wool cloth and place the balloon near a fine stream of water falling from a faucet. The stream of water will deflect toward the balloon. Why? Vary the distance between the balloon and the stream, and observe the displacement of the water stream for different distances. What is the relationship between the displacement of the stream and the distance of separation?

2007-11-27 02:50:13 · 2 answers · asked by Hammad A 1

I've been pondering this for a while, and aside from adding more mass in the form of matter, can't (until recently) imagine how it could be done. Of course, I'm a COMPLETE novice in physics, which might explain why. But recently, partly inspired by a friend of mine exploring the same problem, I came up with this idea:

I was told once (and have not verified it) that because E=mc^2, and M=e/2^2, that mass increases as speed increases, and approaches infinity as the speed of light is approached. If this is true (and PLEASE correct me if it's not), and if gravity is proportional to mass, then wouldn't it be theoretically possible for gravity to be "generated" by speeding up matter to extremely high levels? Such as in a particle accellerator?

Yes, this is a longshot, and in my mind a somewhat clumsy idea, at least in our day and age with our current level of technology. But would it work?

2007-11-27 02:29:35 · 6 answers · asked by The Link 4

By what percentage does the plate’s area decrease?

2007-11-27 02:05:25 · 1 answers · asked by Pascal 4

2007-11-27 01:44:59 · 17 answers · asked by Anonymous

The acceleration of gravity on the surface of Jupiter is 26.7 m/s2. What is the weight on Jupiter of a woman whose weight on Earth is 190 lb?

2007-11-27 00:36:42 · 3 answers · asked by Nicky 1

If height is 2.29cm and base is 4.78cm?

2007-11-27 00:34:03 · 3 answers · asked by Princess of Death 1

If height is 2.29cm and base is 4.78cm?

2007-11-27 00:31:20 · 6 answers · asked by Princess of Death 1

Determine the following or give the meaning of total force and the absolute pressure of the bottom of a swimming pool?

2007-11-27 00:07:57 · 3 answers · asked by ryahdiaz 3

*When you throw a marble and a ping-pong bal at the same force,would it have the same distance??why???
*When you join a stopdance, why is it hard to stop even when the music stops?

THIS ARE ALL RELATED TO SCIENCE...
ANSWER THIS PLEASE..ITS REALLY URGENT

2007-11-27 00:00:33 · 10 answers · asked by Anonymous

A lightning flash is seen in the sky and 9.0 s later the boom of the thunder is heard. The temperature of the air is 12°C.
(a) What is the speed of sound at that temperature? [Hint: Light is an electromagnetic wave that travels at a speed of 3.00 x10^8 m/s.]
m/s
(b) How far away is the lightning strike?
km

2007-11-26 23:41:54 · 1 answers · asked by sportzblock 1

For every action force, there is a simultaneous reaction force equal in in magnitude but in the opposite direction.

Would a catapult be an example of Newton's third law? can someone please give me real life applications, used in society technology or envrionment. Thanks

2007-11-26 23:18:17 · 7 answers · asked by Just wondering 1

A piece of metal weighs 50 N in air, 36 N in water and 41 N in oil. Find the density of the metal and the density of the oil when the metal is completely submerged in both water and oil.

2007-11-26 22:47:51 · 1 answers · asked by n_is_for_ninja 1

2007-11-26 22:46:16 · 9 answers · asked by blue_soul_06 1

2007-11-26 22:35:38 · 8 answers · asked by Anonymous

If mass "resists" change then shouldn't we need to apply extra energy to overcome the resistance? If not, then how would a theoretical mass without inertia be any different than mass WITH inertia. We can't expect that objects would move about and change directions without any force applied to the whatsoever, yet I cannot find anywhere a description of the energy that must be applied just because of the inertia. I have asked questions here before and keep getting answers that address the friction. But I thought that inertia was a property inherent in mass under all conditions. Why would it go away without friction? I investigated "impulse" but that seems different than what I am trying to find.

2007-11-26 21:36:56 · 7 answers · asked by Anonymous

2007-11-26 21:29:46 · 4 answers · asked by Yuks 1

2007-11-26 21:27:27 · 4 answers · asked by Yuks 1

A car with a mass of 1100 kg travels around a banked curve with a constant speed of 35 m/s (about 78 MPH). The radius of the curve is 40 m.

What is the magnitude of the horizontal component of the normal force that would be required to produce this centripetal acceleration in the absence of any friction?

2007-11-26 20:12:34 · 3 answers · asked by Nicky 1

What is the effect of raising voltage when resistance is kept constant?
What is the effect of changing resistance when voltage is kept constant?

2007-11-26 19:54:29 · 4 answers · asked by checked.cherry 2

At 12:00 noon, Twin A with clock stays at rest while Twin B with telescope jumps to √(4/5) speed of light. Twin B, using telescope, observes Twin A's clock going more slowly because of relativistic doppler. After some time, Twin B suddenly reverses course and heads home at √(4/5) speed of light. Still using the telescope, Twin B observes Twin A's clock going faster, again because of relativistic doppler. At 1:00 pm, he notices that Twin A's clock now also shows 1:00 pm. When Twin B arrives back home with Twin A, how much older is Twin A than Twin B?

Bonus question: Why does Twin A, using telescope, NEVER sees Twin B's clock showing the same time as Twin A's clock?

2007-11-26 18:08:06 · 4 answers · asked by Scythian1950 7

A 1.80 kg block slides on a rough horizontal surface. The block hits a spring with a speed of 2.30 m/s and compresses it a distance of 11.0 cm before coming to rest.

If the coefficient of kinetic friction between the block and the surface is 0.560, what is the force constant of the spring?

I'm thinking k=F/X.

K=mass(Potential energy/X)^2

Please help :(

2007-11-26 18:00:45 · 2 answers · asked by revernance 3

In typical transmission lines we have four wires that are made out of copper. Treat these lines as four resistors in parallel. Each of the wires has a diameter of 16 mm. What would be the power loss if the lines were made out of aluminum? Use resistivities of copper= 1.7x10^-8 ohms*m and aluminum =2.8X10^-8 ohms*m
I got an answer of 0.05MW but that's clearly wrong. Could someone give me hand? Thanks!

2007-11-26 17:30:52 · 1 answers · asked by ¿ /\/ 馬 ? 7

i dont understand newton's law of universal gravitation. i've searched everywhere for easier explanations but i couldnt find any. can someone explain it to me so i can understand it??

2007-11-26 16:37:49 · 4 answers · asked by Anonymous

initial angular speed of 18.0rad/s and rolls in a straight line without slipping. If the rotation slows with an angular accelation of magnitude 1.90rad/s^2, how far does the coin roll before coming to rest?

2007-11-26 16:19:30 · 1 answers · asked by mary s 1