Physics - June 2007

2007-06-15 05:58:24 · 8 answers · asked by Anonymous

Coil spring has
unstretched length L = 1000 mm,
spring constant k = 1 N/m,
inductance(sic!) L = 4 mH,
and resistance R = 10 Ohm.

What will be the length of the spring,
if voltage U = 50 V is applied?

2007-06-15 05:40:00 · 3 answers · asked by Alexander 6

Does this explain why electrons can act as both particles and waves?

2007-06-15 05:19:38 · 4 answers · asked by Anonymous

2007-06-15 05:10:14 · 6 answers · asked by fahim_ahmed_khan 1

"I don't know which weapons will be used in WW III, but WW IV will be fought with _____ and _____."


Thanks for playing.

2007-06-15 05:03:58 · 13 answers · asked by ? 5

Gases are classified as gases because of the fact that the atoms are spaced apart from one another. However if this is the case then is the space inbetween the atoms in a gas (eg. air: oxygen, nitrogen etc.) a vacuum?
If it is a vacuum how can we breathe properly?
And what's to stop the 'vacuum' pulling all of the gas atoms together into a liquid/ solid?

2007-06-15 04:52:35 · 7 answers · asked by $i 1

2007-06-15 04:44:05 · 12 answers · asked by Kevin_Mart13 3

The sun in size is enormous. Like placing a penny =the Earth Against a 9ft diameter disk the =Sun. yet our moon is one 6th the size of the earth. The moon fits perfectly over the suns perimiter during a solar eclipse. isnt this just amazing.?Synchronicity at its best. The moon is just in the perfect orbit for this to occur. The hand of God or just pure coincidence.

2007-06-15 04:41:20 · 20 answers · asked by I B 1

2 people stand on 2.0m platform, one on each end. Platform floats parallel to the ground on air, like hovercraft. One person throws 6.0kg ball to the other, who catches it. The ball travels nearly horizontally. Excluding the ball, the total mass of the platform and people is 118kg. Because of the throw, this 199kg mass recoils. How far does it move before coming to rest again?

*I know this question has something to do with the conservation of momentum but I just don't get how it can be solved without knowing the velocities of any member of the system. Also, if you can show your work in solving this question, that would be great. Thanks a lot!

2007-06-15 04:40:59 · 3 answers · asked by Zhan Z 1

A swing carousel consists of rotating circular platform 11m in diameter from which 10 kg seats are suspended at the end of 2.57m massless chains. When the system rotates the chains make an angle of 17.2 degrees with the vertical.

1)what is the speed of each seat? (Answer in units of m/s)
2)If a child of mass 28.8 kg sits in a seat, what is the tension in the chain for the same angle? (answer in units of Newton)

2007-06-15 04:08:36 · 2 answers · asked by Anonymous

2007-06-15 04:04:59 · 12 answers · asked by aung h 1

A loundspeaker diaphragm is producing a sound for 2.3 s by moving back and forth in a simple harmonic motion. The angular frequency of the motion is 6.80 104 rad/s. How many times does the diaphragm move back and forth?
times

2007-06-15 03:49:31 · 2 answers · asked by wildcherrychica1 2

A woman who weighs 5.04 x10^2 N is leaning against a smooth vertical wall, as the drawing shows.
Has a picture of a wall leaning against a wall at a right angle. The angle is 60 degrees. From her feet to her stomach the distance is 1.10m and .440 m above her stomach to her shoulders.
a) Find the force FN (directed perpendicular to the wall) exerted on her shoulder by the wall.
(b) Find the horizontal component of the force exerted on her shoes by the ground.
(c) Find the vertical component of the force exerted on her shoes by the ground.

2007-06-15 03:13:51 · 2 answers · asked by gayle w 1

an ice cube (mass - 1.0kg) slides down an inclined ramp with an acceleration of 4.0 meters per second. Ignoring friction, how much force is pulling the ice cube down from the ramp?

2007-06-15 02:58:22 · 5 answers · asked by Anonymous

2007-06-15 02:56:13 · 8 answers · asked by nandini_breddy 1

And is the brightness of a FILAMENT BULB dependent on the potential difference across it or the current through it?

2007-06-15 02:45:53 · 4 answers · asked by yj_yuanjie 2

2007-06-15 02:39:12 · 6 answers · asked by Anonymous

a 2.0kg block situated on a rough incline is connected to a spring of negligible mass having a spring constant of 100N/m.the block is released from rest when the spring is unstretched, and the pulley is frictionless.the block moves 20cm down the incline before coming to rest. find the coefficient of kinetic friction between the block and the incline.
thx!!

to start with, i know the equation is
Ep = Ee + Eth(thermal energy)

2007-06-15 00:56:39 · 1 answers · asked by Anonymous

So i did this experiment by rolling a marble down a ramp and it turned out that the acceleration decreases? O_O

I thought acceleration was supposed to increase as the marble goes down the ramp? x_x

Or is my data correct? Look at this
http://i164.photobucket.com/albums/u28/vodkapop/phs.png

2007-06-15 00:37:29 · 7 answers · asked by Vienna 3

How do you change weight E.G ...7st to Pounds? (human weighing)

2007-06-14 23:55:41 · 6 answers · asked by Anonymous

Answer my question instantly !

2007-06-14 23:38:15 · 2 answers · asked by arun maari rajha 2

You'll get paid after we get back.Bring your own weapons.Your safety is not guaranteed. I have only done this once!

2007-06-14 23:25:05 · 6 answers · asked by Shoe1 1

2007-06-14 19:48:59 · 5 answers · asked by Anonymous

a) Give an argument why field lines cannot corss.
b) if magnetic charges did exist, what would be the form of Gauss’s Law for magnetism?

2007-06-14 19:16:28 · 2 answers · asked by zubair y 1

3)Land mines made of metal can be detected by sending in a pulse of magnetic filed but plastic land mines cannot be detected in this way. Why?

2007-06-14 19:14:05 · 1 answers · asked by zubair y 1

A current goes around a loop.
a)Find the torque about the vertical axis.
b)Express the torque in terms of the magnetic moment of the current loop.
c)If B=1.5T, I =10A, and the loop is 3*5 cm, find the torque?

2007-06-14 19:11:44 · 1 answers · asked by zubair y 1

1.Can eight 1.5V cells arranged in series can start a car engine?
Explain ur answer.

2.If a battery is fresh,the voltage across the load is almost equal to the e.m.f of the battery.After the battery has been used,its terminal voltage decreases.Explain this observation.
Pls explain what is terminal voltage,is it same with the voltage of the external circuit?

3.Pls calculate....two 1.5 V dry cells are connected in series into the barrel of a flashlight.The internal resistance of the cell are 4.0 ohm and 0.6 ohm.When the flashlight is switched on,a current of 0.5A flows through the bulb.What is the resistance of the bulb?
p/s:The answer stated in my book is 2ohm....and i dunno how to get the answer as i got 5 ohm...confused???

2007-06-14 19:09:55 · 3 answers · asked by emikato_913 2

1)I have emphasized that a magnetic field can only be measured through the magnetic force acting upon a moving charged particle. Yet the commonest way to measure the field is means of the compass. How are the statements consistent with each other?

2007-06-14 19:07:22 · 5 answers · asked by zubair y 1

2007-06-14 18:15:15 · 10 answers · asked by Anonymous

2007-06-14 17:46:57 · 12 answers · asked by kalyandasgupta2005 1