Physics - August 2007

2007-08-26 23:09:03 · 5 answers · asked by Anonymous

HINT : it is related to Black hole...

2007-08-26 21:27:52 · 2 answers · asked by me only 1

True or False
The trigger circuit can be actuated only by a signal from internal oscilloscope circuit.

2007-08-26 20:03:41 · 2 answers · asked by Anonymous

When startled, an armadillo will leap upward. Suppose it rises 0.544 m in the first 0.200 s. (a) What is its initial speed as it leaves the ground? (b) What is its speed at the height of 0.544 m? (c) How much higher does it go?

2007-08-26 18:57:18 · 4 answers · asked by Anonymous

The coherence length must be altered when passing through the fiber.So we must be able to determine certain characteristics like pulse dispersion or intensity variation using coherence length as one of the parameter.

2007-08-26 18:30:24 · 2 answers · asked by swarna l 1

2007-08-26 17:56:41 · 5 answers · asked by Anonymous

2007-08-26 17:44:37 · 5 answers · asked by mikesell 1

Ok, I want to understand this, I have the answer but I need to know why we got that answer, if we have a closed loop system with a given transfer function:

G(s) = 10 / (s+11)

What is the steady state output of the system when an input of:

2 cos (2t - 45)

is presented to the system.

the answer I have is 1.79 cos (2t - 55.3)

Please Explain, Thanx in advance.

2007-08-26 17:25:06 · 2 answers · asked by 037 G 6

determine the stopping distances for a car with an initial speed of 95 km/h and human reaction time of 1.05, for an acceleration (a) a =-4.0m/s^2 (b) a=-8.0 m/s^2

2007-08-26 17:21:56 · 2 answers · asked by Anonymous

toy rocket is launched vertically from ground level (Y=0), at time, t=0.0s. The rocket engine provides constant upward accleration during the burn phase. At the instant of engine burnout, the rocket has risen to 64 m and aquired a velocity of 60m/s. The rocket continues to rise in unpowered flight, reaches max height, and falls back to the ground. The time interval, during which the rocket engine provides upward acceleration, is closest to?

2007-08-26 16:20:06 · 1 answers · asked by Anonymous

a world class sprinter can burst out of the blocks to essentially top speed [about 11.5 m/s] in the first 15.0 m of the race. What is the average acceleration of the sprinter and how long does it take her to reach that speed?






=i dont get it help! :( i dont get the concept of velocity or accerleratation. : (

2007-08-26 16:12:05 · 1 answers · asked by Anonymous

at some point t = 0, now t = 6000 or whatever, t = 6 x10^9, our origin is not the point of my question. but rather how did we get here, to this moment in time? what is the mechanism by which time (t) increases, or is it the mechanism by which everything else occurs? I guess it would depend on whether time is constant or a variable.

2007-08-26 16:01:58 · 15 answers · asked by Gruntled Employee 6

Two cars cover the same distance in a straight line. Car A covers the distance at a constant velocity. Car B starts from rest, maintains a constant acceleration, and covers the distance in the same time as car A.
Both cars cover a distance of 450 m in 220 s. Assume that they are moving in the + x direction.

(c1) What is the algebraic expression for the acceleration aB of car B? Express your answer in terms of the car's displacement L and the time t.
(c2) What is the acceleration aB of car B? Include an explicit plus or minus sign along with your numerical answer.

2007-08-26 14:48:36 · 1 answers · asked by Anonymous

Two cars cover the same distance in a straight line. Car A covers the distance at a constant velocity. Car B starts from rest, maintains a constant acceleration, and covers the distance in the same time as car A.
Both cars cover a distance of 450 m in 220 s. Assume that they are moving in the + x direction.

(a1) What is the algebraic expression for the final velocity vB of car B? Express your answer in terms of the car's displacement L and the time t.
(a2) What is the final velocity vB of car B? Include an explicit plus or minus sign along with your numerical answer.

2007-08-26 14:47:12 · 1 answers · asked by Anonymous

2007-08-26 14:35:08 · 3 answers · asked by touchdowntaron 1

When an object falls through the air, there is a drag force that depends on the product of the surface area of the object and the square of its velocity. Fair = CAv^2. Where C is a constant. Determine the dimensions of C.

I know that Force is (kg)(m)/(s^2).
Area = m^2
v^2 = m^2/s^2

I have to find what units C has to have in order for both sides of the equation to be dimensionally correct.

2007-08-26 14:32:05 · 5 answers · asked by Jackie 2

A spelunker (cave explorer) drops a stone from rest into a hole. The speed of sound is 343 m/s in air, and the sound of the stone striking the bottom is heard 1.80 s after the stone is dropped. How deep is the hole?

*A bunch of people gave me wrong answers to this and as a result I only have 1 submission left* Please make sure the answer is correct, it is a two step thing I Believe.

2007-08-26 14:16:04 · 6 answers · asked by Anonymous

what are two specific places in everday life in which solenoids are used? how do solenoids function in each use?

2007-08-26 14:09:16 · 5 answers · asked by Anonymous

2007-08-26 14:08:48 · 1 answers · asked by Anonymous

2007-08-26 14:07:36 · 1 answers · asked by Anonymous

2007-08-26 13:56:09 · 3 answers · asked by Anonymous

i want to know!!

2007-08-26 13:39:19 · 9 answers · asked by Anonymous

So, let's take a paradox - two things that cannot exist together.

Let's assume that the two things DO coexist.

Is this possible??? Huh, is it???

2007-08-26 13:21:48 · 3 answers · asked by Anonymous

According to Brian Greene's book, The Elegant Universe, page 329, "... a three-dimensional sphere inside a Calabi-Yah space can collapse without an ensuring disaster, because a three-brane wrapped around it provides a perfect protective shield." Then on page 324, he writes: "... the three-brane can wrap around and completely cover a three-dimensional sphere. ... a three-brane has three extended dimensions." Then, on his CDs, he ask the question: could our universe be a three-brane?

So, is a three-brane small like the Planck distant or somehow large like our universe? And, what would cause space to rip or tear in the first place?

2007-08-26 13:13:11 · 1 answers · asked by Bob D1 7

Some modern toys are now manufactured with sensors that read & respond to brain waves. As headphones can also be used as a microphone, and a microphone can be used to emit sound (though each operates less efficiently at the task for which it was _not_ designed), might it also be possible to "transmit" a signal from such a sensor that could provoke some sort of response in the brain via the same features the brain uses to broadcast brain waves?

2007-08-26 13:06:34 · 4 answers · asked by uncleclover 5

2007-08-26 13:01:16 · 8 answers · asked by 00000000 1

I once read in school that magnetism comes out of one side of a magnet, goes around, and then goes back into the other side of the magnet. Like making a circle.

Do we know HOW magnetism is moving out, and in, the magnet?
What is making the - energy? - that makes magnetism, move?

I think of energy stored in a battery. But in a battery, the energy goes out, does not come back to the battery.

2007-08-26 13:00:35 · 1 answers · asked by Anonymous

which metric unit and prefix would be the most convenient to measure each of the following?
a.the diameter of a giant sequoia tree
b.the diameter of a human hair
c.time necessary to blink your eye
d.mass of gasoline in a gallon
e.mass of cold virus
f.amount of aspirin in a tablet
g.mass of concrete to pave a parking lot



thanks guys i owe you and if you could explain

2007-08-26 11:12:44 · 8 answers · asked by leslie g 3

2007-08-26 11:05:48 · 5 answers · asked by Al 2

a roof tile falls from rest from the top of a building. an observer inside the building notices it takes 0.20 seconds for the tile to pass her window. whose height ius 1.6m. how far above the top of this window is the roof?

If anyone could help me, thanks alot! I am really confused what to do

2007-08-26 11:03:37 · 2 answers · asked by Takkun 1