Physics - April 2007

A 400 ohm resistor is connected with an inductor of inductance 0.2 H and a capacitor of capacitive 30 x 10 raised to -6 faraday. The combination is connected to a 220V, 60 cycle source. Find its joint reactance and impedance..

2007-04-27 16:17:49 · 2 answers · asked by >bLueeyes< 2

While on the train to night in Chicago I saw several arcs of electricity between the train and the power rail - I believe they occur at joints on the electrical rail.

I have to believe there is some current lost due to heat and and flash, if so, how much? What is the formula or ratio? Is more energy lost during an arc of greater distance?

2007-04-27 16:10:30 · 2 answers · asked by littlebike 2

2007-04-27 15:32:07 · 5 answers · asked by James Z 1

A coil is wound on an iron former of mean magnetic length of 25cm and cross-section of 4cm^2. The relative magnetic permeability is 1000, leakage, fringing and losses of all types are neglected. The coil will be connected to an AC source of frequency = 400Hz so that the peak current drawn does not exceed 0.1A and the iron operates at a peak flux density of 0.9T.

a) By using Ampere's law, determine the number of turns, N of the coil to meet this specification.

b) By using Faraday's law, obtain an expression relating the peak supply voltage to the peak magnetic field intensity.

c) Calculate the maximum permissible peak supply voltage so that the specified peak current and flux density are no exceeded.

2007-04-27 15:31:54 · 2 answers · asked by AlexTan 3

2007-04-27 15:00:30 · 7 answers · asked by Anonymous

I have a watch that says water resist to 4 ATM

2007-04-27 14:34:38 · 4 answers · asked by Rey D 2

A rectangular loop of wire is moving toward the bottom of the page with a speed of 0.019 m/s (see the drawing). The loop is leaving a region in which a 2.9 T magnetic field exists; the magnetic field outside this region is zero. During a time of 2.0 s, what is the magnitude of the change in the magnetic flux?

http://www.webassign.net/CJ/22_16.gif

2007-04-27 14:22:24 · 1 answers · asked by Alan l 1

In terms of Newton's third law why someone tries to jump from a canoe to a riverbank may fall into the water??

2007-04-27 13:57:28 · 2 answers · asked by Anonymous

After being pushed and released a 50-kg crate slides across a factory floor. Friction on the sliding crate is 200 N. What is the crate's acceleration?

I knot that the equation to ding acceleration is A=F/M but can i use 200N (friction) in the place of F(force)???

2007-04-27 13:56:04 · 4 answers · asked by BrbE 3

If you were in your car, and there was a fly flying around inside the car (but not landing on anything), and you accelerated to 100 mph, would the fly have to fly 100 mph to keep up with the car to remain in the air? Why would he have to do that outside the car but not inside?

2007-04-27 10:56:00 · 4 answers · asked by FUNdie 7

ok so my science question says:
describe a sport(i chose golf) that would use comparative motion of objects to improve the effectivness of the objects in motion
Your answer must have a detailed explanation of the sport and explain why the analysis of motion is important to the career.
Explain the types of motion utilized in their measurements.

HELP!

2007-04-27 10:41:12 · 2 answers · asked by jada jenn 2

Still helping my grandaughter with her studies. Can you answer these questions? Thankyou so much.


1.)A worker applies a force of 550N in sliding a block of wood 15.0m along a surface. The work output is determined to be 5.00x10^3 J. Calculate the workers efficiency.

2.)On a camping trip, the following scenario occurs:
I A camper rubs a match on a gritty surface igniting a match.
II The match is then used to ignited a pile of wood kindling, creating a bonfire
III While standing by the bonfire, the camper senses that the part of his body facing the fire is warm while his backside remains cool.
IV Another group of campers across the lake spots the bonfire.

Which of the above describes a conversion of mechanical energy to heat?

3.)Which of the above describes a conversion of radiant evergy heat? I, II, III OR IV?

Thankyou so much!

Thankyou I am so grateful.

2007-04-27 09:44:32 · 6 answers · asked by Grandpa Donald 1

My tiny brain cannot wrap around the idea of past present and future happening all at once. Is there lay terms for this theory and was it disproven?

2007-04-27 09:20:47 · 3 answers · asked by rebamarnette 1

2 Balls of the same metal. volume each one (0.0002 m3). one Impermeable and the other oner rivet . when they were placed in water (density 1000 kg / m 3 ) we found that one sank and the other attached. Find The size of the vacuum created in the ball rivet. note that the density of the metal ( 2707 kg / m 3) (G= 9.8 m / s 2) .

2007-04-27 09:16:30 · 1 answers · asked by !!!NAPSTER!!! 1

1.A concrete highway is built of slabs 14m long (20 degrees celcius). How wide should the expansion cracks be at 20 degrees celcius) between the slabs to prevent buckling if the range of temperature is -30 degrees celcius to +50 degrees celcius?
2.A quartz sphere is 14.5cm in diameter. What will be its change in volume if it is heated from 30 degrees celcius to 200 degrees celcius?

2007-04-27 08:42:34 · 1 answers · asked by petite fille 2

A long horizontal wire carries a current of IT = 48.8 A. A second wire (I), made of 2.50 mm diameter copper wire and parallel to the first but L = 13.3 cm below it, is held in suspension magnetically, as seen in the figure below. What is the current in the lower wire (Use right as the positive direction)?

What is the current in the lower wire if the second wire is suspended L = 13.3 cm above the first due to the latter's field.

How do you solve this complicated problem?? I am so lost and confused.





Here is a diagram: http://i151.photobucket.com/albums/s126/beautyqueenjustine/gian2056.gif

2007-04-27 08:18:48 · 1 answers · asked by Anonymous

2. A block of mass M, at rest on a horizontal
frictionless table, is attached to a rigid support
by a spring of constant k. A bullet of mass m
and velocity v strikes the block. The bullet remains embedded in the block.

1) (a) Determine the velocity of the block immediately after the collision (in terms of M,m and v).
Hints: What kind of collision is it? Is mechanical energy conserved? Is momentum conserved?

2) (b) Determine amplitude of the resulting simple harmonic motion (in terms of M, m,v and k).
Hints: In which form is the energy right after the collision? Is mechanical energy
conserved in simple harmonic oscillations? How amplitude is related to
the energy?

http://physics.syr.edu/courses/PHY211.07Spring/hw/HWProblemSet12.pdf

2007-04-27 08:12:42 · 1 answers · asked by ? 1

2007-04-27 07:53:47 · 8 answers · asked by John J 3

2007-04-27 07:49:09 · 5 answers · asked by Alexander 6

2007-04-27 07:45:32 · 2 answers · asked by nothingspecial 1

2007-04-27 07:35:22 · 5 answers · asked by Anonymous

The object falls on one edge of the vertical tubular column. What I wish to know is what is the mechanics of the failure and what forces are involved. Does the column fail because of a compressive force causing brittleness or that the forces involved exceed the tensile strength.

How can the impact force be calculated and where can I find information about the limiting forces for failure of the materiel of the column in such a situation. Please note I work in the metric system.

2007-04-27 07:30:41 · 2 answers · asked by Rodney 1

2007-04-27 07:29:14 · 5 answers · asked by Alexander 6

2007-04-27 07:26:44 · 6 answers · asked by Rock ah About 3

Please HELP!

2007-04-27 07:12:41 · 1 answers · asked by Anonymous

tell me

2007-04-27 07:05:47 · 6 answers · asked by BiANCA 2

When a narrow laser beam passes through a fine wire mesh before arriving at the wall, it forms a complicated pattern of bright spots on the wall. This pattern of spots would not occur if you sent a flashlight beam through the mesh because light from the flashlight (Select one)


A) is horizontally polarized, while laser light is vertically polarized.

B) is vertically polarized, while laser light is horizontally polarized.

C) is not a single electromagnetic wave.

D) cannot be sent through a single opening of the mesh.

WHY?

2007-04-27 06:47:05 · 2 answers · asked by freepeopleurbangirl34 1

A bright beam of light from a laser passes through a tiny pinhole on its way to a projection screen on the other side of the room. Since the beam was several millimeters in diameter, the pinhole blocks most of the beam's light. After passing through this pinhole, the remaining light (Select one)

A) forms an extremely narrow beam that illuminates only a tiny spot on the projection screen-a spot the same diameter as the pinhole.

C) spreads relatively rapidly so that it forms a rather large spot on the projection screen.

D) changes frequency and color because it experiences destructive interference inside the pinhole.


Why?

2007-04-27 06:44:01 · 2 answers · asked by freepeopleurbangirl34 1

Semi-infinite spring of specific stiffness s = 8N and
linear density q = 0.5 kg/m originally rests on frictionless
horizontal surface. Force F = 6N is applied at moment
t=0 to the hook at free end of the spring and maintained
constant thereafter.

<=== F ===C-wwwwwwwwwwwwwww......


What is terminal speed of the hook?

2007-04-27 06:38:51 · 1 answers · asked by Alexander 6

It is true that in between two objects there is infinite space.

With that being said then you can never touch anything being as there will always be an infinite space in between the two objects. then how do we hurt ourselfs with a bullet if the bullet never actually touches us?

All comments welcome.

2007-04-27 06:24:20 · 8 answers · asked by mike 1