Physics - May 2007

2007-05-30 20:30:21 · 4 answers · asked by aungohnmar 1

If two lightning bolts hit exactly the same place at exactly the same time in one frame of reference, is it possible that observers in other frames will see the bolts hitting at different times or at different places?

2007-05-30 20:23:25 · 4 answers · asked by Anniepannie06 2

Astronomers view light coming from distant galaxies moving away from the Earth at speeds greater than 10% the speed of light. How fast does this light meet the telescopes of the astronomers?

2007-05-30 20:20:57 · 4 answers · asked by Anniepannie06 2

How much work (in joules) is done by a force that moves a charge 2 coulombs through a distance of 10 cm in a constant electric field of 7 V/cm ?
Please all freind help me soon for solve this question??

2007-05-30 20:20:36 · 2 answers · asked by zubair y 1

2007-05-30 20:16:10 · 10 answers · asked by Anonymous

Whats Will be the direction of the electric filed in the each following circumstances.
(a) in the middle of square with four equal positive charges at the corners.
(b) in the middle of square with 3 equally positive and negative charge at the corners.?
(c) at the center of hollow sphere with charges ditributed uniformly on the surface.?
(d) at the centre of a hollow sphere with the charge on one hemisphere is positive, and the chrage on the other hemisphere is negative.

2007-05-30 20:13:15 · 2 answers · asked by zubair y 1

Why is that if energy is conserved the string of a pendulum never reaches the height it was dropped from?

2007-05-30 20:12:19 · 2 answers · asked by Anonymous

Lately in the office whenever I press the button for the lift or touch a metal door handle I get zapped.
Can you explain what causes this and why it happens to me more than other people at work?

p.s I'm in Australia

2007-05-30 20:07:36 · 6 answers · asked by Jon 2

Is achieving faster then light technology travel possible (yea I know even if it is, not in our life time) and if so, could we in theory travel in time???

2007-05-30 20:05:21 · 4 answers · asked by Hakim H 1

I am taking a physical science class and this is a tuff one.....please help....thanks!

2007-05-30 19:53:56 · 7 answers · asked by sugar_and_spice 2

Help!!!

2007-05-30 19:34:57 · 3 answers · asked by sugar_and_spice 2

An explosion breaks an object into two pieces, one of which has 1,5 times the mass of the other. If 17,500 J were released in the explosion, how much kinetic energy did each piece acquire?

2007-05-30 19:14:20 · 2 answers · asked by Nomad 1

On a serve, a tennis ball leaves Serena Williams racket at 65.0 m/s. If the ball's mass is 0.0600kg it is in contact with the racket for 0.300s, what's the average force on the ball?

2007-05-30 19:13:16 · 2 answers · asked by Nomad 1

Any answer for this random question?....

I've already looked in the Net, but I had no luck at all...-_-;

Thanks for reading, and sorry for the crappy english.

2007-05-30 19:05:17 · 5 answers · asked by ReyDeEspadas 1

I am building an air cannon am trying to figure out what the ideal weight of my projectile is. I have a chamber volume of about 4800 cu/in exiting through a 2" ball valve. The barrel is 15' long 2" dia. The ball is 1 7/8" dia. Given the amount of force applied to the ball, (surface area x 150 psi) at what point does the weight slow its exit velocity? Is it a bell curve? Is this detailed enough? The gun will be fired at a 45 degree angle. Basicall I need to know at what point the weight will start to decrease the distance I can shoot it. Pushing a Ping pong ball with 150psi vs a ball of the same size that weighs 3lbs.
Thanks for any help!
Rich

2007-05-30 18:52:27 · 1 answers · asked by Anonymous

An airplane travels 3100km at a speed of 790km/h and then enounters a tailwind that boosts the speed to 990km/h for he next 2800km.

a)What was the total time for the trip?
I calculated this to be 6.75h
b) whatwasthe average speed of the plane for the trip?
I just cant figure out how to set this up?

2007-05-30 17:40:55 · 4 answers · asked by 11 2

water gets hard to become ice.
water vapour gets solid to form snow-this is what i know.

2007-05-30 17:18:22 · 8 answers · asked by Anonymous

A spring is fixed at the bottom end of an incline of inclination 37(degree). A small block mass 2 kg starts slipping down the incline from a point 4.8 m away from the spring. The block compresses the spring by 20 cm, stops momentarily and then rebounds through a distance of 1 m up the incline. Find :-

a) the friction co-efficient between the plane of the incline and the block
b) the spring constant of the spring. Take g=10 m/(s^2)


diagram is available in HC Verma (vol^m 1) , page 135 , problem no. 43 , fig- 8-E7

The original answer is ....
a)0.5 b)1000 N/m

2007-05-30 17:17:28 · 2 answers · asked by AD 1

If heat moves from warmer places to cooler places, then how can an animal lose body heat when its environment is warmer than its body?

2007-05-30 16:44:40 · 4 answers · asked by nicole h 1

If white light were emitted from Earth's surface and observed by someone in space, would its spectrum be continuous? Explain.

2007-05-30 16:43:06 · 2 answers · asked by Anonymous

I was reviewing my notes about Schematic diagrams and found that it's saying that "Cell (the long bar is the positive end)".

I've been thinking that the shorter bar reprsent positive end, and electricity goes from negative end to positive end (the longer bar to shorter bar), so I always drew Schematic diagram based on that.

(eg, when it said to draw a switch that turn off everything, I drew it just after the longer bar which I've been thinking to be the negative end.)
I even got full mark for drawing them.

Now, I'm totally screwed.
Could you please explain what's happened??!

2007-05-30 16:01:48 · 3 answers · asked by Sayaka 1

A packed bundle of 100 long, straight, insulated wires forms a cylinder of radius R=.5cm

a. if each wire carries 2A, what are the magnitude and direction of the magnetic force per unit length acting on a wire located .2cm from the center of the bundle?

don't know what to do.

2007-05-30 15:32:21 · 1 answers · asked by laxgurl87 2

Part a of the drawing shows a bucket of water suspended from the pulley of a well; the tension in the rope is 76.5 N. Part b shows the same bucket of water being pulled up from the well at a constant velocity. What is the tension in the rope in part b?

http://img264.imageshack.us/my.php?image=p446ca2.gif


It's due at midnight!

2007-05-30 15:27:10 · 3 answers · asked by Kat 1

There are lot of video search results available as educational videos, which are very much helpful for me as I'm a teacher. So please say me how to download them in simple steps.If you can suggest some more free video stuff for teaching physics ,you are most welcome.

2007-05-30 15:08:37 · 2 answers · asked by joe kutti 1

2007-05-30 15:03:26 · 10 answers · asked by Moanika 6

how do all encompassing mirrors help keep out heat?

2007-05-30 14:45:24 · 2 answers · asked by Anonymous

a circular orbit with a period of 7.08 x 10^3 s and orbital speed of 3.4 x 10^3 m/s. The mass of the GS is 930kg and the radius of Mars is 3.43 x 10^6 m.
A. Calculate the radius of the GS orbit
B. Calculate the mass of mars

2007-05-30 14:44:57 · 2 answers · asked by manthisissohard 2

2007-05-30 14:44:20 · 4 answers · asked by Anonymous

2007-05-30 14:30:54 · 4 answers · asked by msxtc4u 1

A person whose eyes are H = 1.59 m above the floor stands L = 2.29 m in front of a vertical plane mirror whose bottom edge is 43 cm above the floor, What is the horizontal distance x to the base of the wall supporting the mirror of the nearest point on the floor that can be seen reflected in the mirror?

2007-05-30 14:00:19 · 4 answers · asked by Anonymous