Physics - February 2007

to get Eaverage=Eaverage(N,V,beta)=Ej(N,v)e^-betaEj(N,v)/e^-betaEj(N,v).

2007-02-19 12:59:40 · 1 answers · asked by zizi m 1

two people on earth. one at the equator and one at the north pole. which one has the larger centripetal acceleration? is it the one at the north pole because his period is much shorter and therefore his acceleration is greater?

2007-02-19 12:56:05 · 4 answers · asked by Anonymous

What I am trying to figure out is what single equivalent resistor could replace all of these resistors in this particular circuit. Since i can't draw it i will explain it to you. There is a pair of resistors in parallel ...5 and 9 ohms. Combining these brings about a pair in series... 2 ohms and the answer you got with combining the ones in parallel ( i got 2 + 3.2142857= 5.2142857) Now this single equivalent resistor is parallel to one...14 ohms. In doing this I got 12.22782 for the equivalent resistor to replace all of these, but it is wrong. Any ideas....Much thanks in advance

2007-02-19 12:50:37 · 4 answers · asked by Anonymous

2007-02-19 12:38:41 · 5 answers · asked by haitianqueen_609 1

Ok this may be kinda hard to explain but the question is

What is the theoretical mechanical advantage for each of the three lever systems shown? Since you can't see the pics ill explain wat they look like

Lever 1-a straight bar just sitting there at rest with a triangle underneath it with a box resting on top of it to the far right and then on the far left an arrow pointing down.

Lever 2-Now the triangle is underneath the bar on the far left and the bar is tilted upwards.The box is in the middle and the arrow is on the far left pointing right.

Lever 3-The bar is just sitting again and the triangle is to the far left. the box is on the far right and the arrow is pointing up in the middle.

OK i understand that that probably made ZERO sense but maybe if you are a physics expert you can make some sense of it. Or atleast someone can explain to me how you figure out theoretical mechanical advantage just by looking at picture!! THANKS SOOO MUCH!!!

2007-02-19 12:22:14 · 3 answers · asked by Jane A 3

A 0.80 m length of wire is formed into a single-turn, square loop in which there is a current of 28 A. The loop is placed in a magnetic field of 0.3 T. What is the maximum torque that the loop can experience?

2007-02-19 12:11:50 · 3 answers · asked by christian m 2

How are Potential energy and Kinetic energy used in catapults?

2007-02-19 12:06:29 · 6 answers · asked by Anonymous

the power supply of a battery that is

2007-02-19 12:05:37 · 1 answers · asked by Logan 4

At school the really religious kids keep telling me about how Stephen Hawking proved the existance of a higher being through quantum physics, but they never tell me what the experiment was. I figure if it's true, then the Christian Right would've grabbed a hold and never let go of it in the media, and quite frankly everyone would believe in God (since there would be proof of it). Anyone mind pointing me to the direction of this proof? I can't find it anywhere

2007-02-19 12:03:51 · 6 answers · asked by Captain Obvious 2

and is pulled at constant speed by a rope inclined at 19.6° above the horizontal. The sledge moves a distance of 20.9 m on a horizontal surface. The coefficient of kinetic friction between the sledge and surface is 0.500.

a) What is the tension in the rope?____N

b)How much work is done by the rope on the sledge?____kj

c)What is the mechanical energy lost due to friction?_____kj

need help on this on guys. Can you show me how to get to the solution. Thanks ;)

2007-02-19 11:59:58 · 1 answers · asked by cosmo 1

2007-02-19 11:59:54 · 6 answers · asked by tiagraham17 2

No sound, able to make 90 degree turns. Able to deify gravity. Instant acceleration.

2007-02-19 11:56:23 · 2 answers · asked by alone 2

If a car (mass=100tons) has a coefficient of friction=0.02, how much force must the engine produce if the locomotive is to accelerate at 1 m/s^2?

2007-02-19 11:53:38 · 1 answers · asked by ellyvstheworld 1

Hi,

A 40 micro F capacitor that had been charged to 30 V is discharged through a resistor. The capacitor voltage as a function of time is shown in Figure P31.73, in which each interval on the horizontal axis equals 2 ms. What is the value of the resistance?

Figure 31.73:
http://i137.photobucket.com/albums/q208/infinitbelt/p31-73alt.gif

Any ideas?


Thanks!

2007-02-19 11:42:49 · 1 answers · asked by Anonymous

You have been asked to design a "ballistic spring system" to measure the speed of bullets. A bullet of mass 2.90 g is fired into a block of mass 1.80 kg. The block, with the embedded bullet, then slides across a frictionless table and collides with a horizontal spring whose spring constant is k=32.0 N/m. The opposite end of the spring is anchored to a wall. What was the speed of the bullet if the spring's maximum compression is 14.4 cm?

2007-02-19 11:36:34 · 2 answers · asked by N 1

2007-02-19 11:34:25 · 2 answers · asked by Anonymous

A capacitor in an RC circuit is initially uncharged. What is the charge on the capacitor being charged up by a 25 V battery after a period of 2 time constants of the RC circuit. ( C=15uF or 1.5 x10-5, R=unknown)? Thank you so much in advance I have tried to work out this problem for over an hour! :)

2007-02-19 11:27:26 · 1 answers · asked by Anonymous

A block whose weight is 45.0N rests on a horizontal table. A horizontal force of 36.0N is applied to the block. The coefficients of static and kinetic force are 0.650 and 0.420, respectively. Will the block move under the influence of the force, and, if so, what will be the block's acceleration? Explain your reasoning.

While working through this problem I was able to find that Fnorm=(45.0N)(9.8m/s^2)=441N
also that fstatic^max=(.650)(441)=286.65N and fkinetic=(.420)(441)=185.22N.
However, when I calculated a using fkinetic=ma then I get the answer as being a=4.116, which my book says is incorrect (correct answer is 3.72m/s^2). Where are my calculations wrong?

2007-02-19 11:15:00 · 2 answers · asked by ellyvstheworld 1

I've heard so many reasons why the water spins down the toilet one way in some places, and other ways in other places. Does anyone know the actual reason why water goes down the toilet/plug hole in the way that it does?
Where does it change?
Is there a plce on earth where it simply drops straight down without spinning?

2007-02-19 10:51:35 · 17 answers · asked by Straight Talker 3

2007-02-19 10:48:06 · 4 answers · asked by alex 1

"Consider a mass m hanging vertically from the end of a spring of force constant k. In equilibrium, the mass rests at a position y = y0 = mg/k. Starting from Newton’s second law, show that if the mass is displaced from equilibrium a distance A and then released, it will follow simple harmonic motion about the position y0." Good luck!

2007-02-19 10:46:12 · 1 answers · asked by Goose 2

Coasting along at 7.10 m/s, a 60.0 kg bicyclist on a 7.60 kg bicycle encounters a small hill. If the speed of the bicyclist is 6.00 m/s at the top of the hill, how much work was done on the bicyclist and her bike?

Can anyone show me how to do this? Thanks.

2007-02-19 10:46:01 · 1 answers · asked by PhyzicsOfHockey 2

Assume the earth is spherical. Relative to someone on the rotation axis, what is the linear speed of an object on the surface if the radius vector from the center of the earth to the object makes an angle of 58.0° with the axis of rotation. The radius of the earth is 6.37×103 km.

2007-02-19 10:14:32 · 5 answers · asked by bud 1

a.)How strong is the magnetic field 16 cm away from it?
T
b.)What percentage of the Earth's magnetic field (5.00 * 10^ -5 T) is this? %

2007-02-19 10:06:07 · 1 answers · asked by Jade m 1

cont'd... when perpendicular to a 0.81 T magnetic field?
N/m
b.) What if the angle between the wire and field is 60.0 degrees?
N/m
I would appreciate ANY help w/ this problem! Thanks!

2007-02-19 09:58:32 · 4 answers · asked by Jade m 1

2007-02-19 09:52:38 · 2 answers · asked by death angel 1

I'm having problems with part B of this problem. Any help anyone can give me would be greatly appreciated. Please see below:

Two long, straight wires are separated by 0.12 m. The wires carry currents of 5.5 A in opposite directions, as the drawing indicates.

http://www.webassign.net/CJ/21_56.gif

(a) Find the magnitude of the net magnetic field at the point A.
Answer is 2.9333e-5 T

(b) Find the magnitude of the net magnetic field at the point B. (in T)

It was my belief that the fields should cancel each other out and the magnitude should be 0 T at point B, but the answer is wrong when I submit it. Am I missing something?

2007-02-19 09:51:23 · 2 answers · asked by larkinfan11 3

2007-02-19 09:49:38 · 1 answers · asked by happygirl 2

How do I Measure T for four different lengths of string. Time 10 cycles. Is there a pattern? B) How does period T change with different springs using the same mass? Use 2 springs and time ten cycles. C) For one particular mass and string, measure the period, and compare to the "theoretical" value T= 2 pie L/G, where L =Length of string and G= 9.81 M'/S squared. Are these values close? I am very confused about this, and could use some help.

2007-02-19 09:42:18 · 1 answers · asked by Jujie 1

I know how to deal with tension in a massless cord, but what if the cord has mass? Here is the specific question:

A block of mass M is attached to a cord of mass m and length , which is fixed at one end. The block moves in a horizontal circle on a frictionless table. If the period of the circular motion is P, find the tension in the cord as a function of radial position along the cord, 0 <= r <= L.

Apparently an integral needs to be set up, but I don't know how to approach it.

2007-02-19 09:40:26 · 2 answers · asked by Jacqueline Sherry 1