Physics - April 2007

i mean the floating laser that hover over the 2 1/2 inch by 3 inch handheld projector. that project any image programed to recreate.

2007-04-22 15:31:52 · 1 answers · asked by Thinkabouit 2

http://img179.imageshack.us/my.php?image=knightfigure2540at9.jpg

2007-04-22 14:31:48 · 1 answers · asked by Anonymous

2007-04-22 14:26:27 · 3 answers · asked by corey 1

2007-04-22 14:10:54 · 2 answers · asked by Jackie3421 2

What velocity would a proton need to circle Earth 1200 km above the magnetic equator, where Earth's magnetic field is directed horizontally north and has a magnitude of 4.00x10^-8 T?

2007-04-22 13:21:23 · 2 answers · asked by Tennis2127 2

i tried Google, Yahoo, Ask,......etc.. STILLL NO LUCK! anyone know if it will have an impact on the world? ? with source plz

2007-04-22 13:18:02 · 6 answers · asked by oikos 2

The X-rays used in medical imaging travel through tissue relatively easily but are mostly absorbed by bone. Why?

2007-04-22 13:15:27 · 4 answers · asked by Anonymous

he fallout from a nuclear explosion and the waste from a nuclear reactor contain radioactive isotopes. The atoms of these isotopes differ from stable atoms in that.....

2007-04-22 13:14:20 · 1 answers · asked by Anonymous

2007-04-22 13:00:01 · 6 answers · asked by James De Leo 1

Piston 1 in Figure P9.24 has a diameter of 0.25 in.; Piston 2 has a diameter of 1.1 in. In the absence of friction, determine the force, , necessary to support the 500 lb weight.
_________ lb
http://www.webassign.net/sf/p9_24.gif

2007-04-22 12:48:43 · 4 answers · asked by Emma 1

1.) Two automobiles are equipped with the same single-frequency horn. When one is at rest and the other is moving toward an observer at 15 m/s, a beat frequency of 5.0 Hz is heard. What is the frequency the horns emit? Assume T = 20°C.

2.) Two trains emit whistles of the same frequency, 275 Hz. If one train is at rest and the other is traveling at 45 km/h away from an observer at rest, what beat frequency will the observer detect?

I have been trying to do these problems for quite a long time already, but I just can't seem to get it. Can someone please help?! Thanks.

2007-04-22 11:17:57 · 1 answers · asked by abc123 1

shivering when you are cold actully warms you up....desert jackrabbits have large ears to keep them cool...

2007-04-22 11:01:40 · 5 answers · asked by Anonymous

thanks =]

2007-04-22 09:18:45 · 2 answers · asked by Edwin C 2

if we have a chance to build an electricity generation system in mercur, which one would be the best among the all energy generation systems? why?
have a nice day...

2007-04-22 08:46:18 · 1 answers · asked by Enis T 2

i have to explain a model of it

2007-04-22 08:19:44 · 2 answers · asked by pop 2

A uniform ladder of mass 30kg and length 10m has its base resting on rough horizontal ground and its top against a smooth vertical wall. The ladder rests in equilibrium, at 60 degrees to the horizontal, with a man of mass 90kg standing on the ladder at a point 7.5m from its base. Find the magnitude of the normal reaction and of the frictional force at the ground.

The answers: 1176N, 467N respectively.

I thought I worked out an answer, but I somehow got 1250N (or something along those lines) for my normal reaction, and my working isn't all that plausible, really, so- any help'll be greatly appreciated! Thanks. :)

2007-04-22 08:14:48 · 2 answers · asked by kimiessu 2

Question: There are 5620 lines per centimeter in a grating that is used with light whose wavelength is 471 nm. A flat observation screen is located at a distance of 0.750 m from the grating. What is the minimum width that the screen must have so the centers of all the principal maxima formed on either side of the central maximum fall on the screen?

Book Answer: 1.95 m

I am having a lot of difficulty comprehending the last part of the question. I usually have an approach to a problem though, but for this one...I feel like it's impossible to have one without seeing how to do this problem!

2007-04-22 07:53:24 · 1 answers · asked by Jimmy 3

if either, have the greater rotational speed.

2007-04-22 07:46:12 · 1 answers · asked by Justin M 1

A diving board of length L = 3.00 is supported at a point a distance 1.00 m from the end, and a diver weighing 550 Nstands at the free end . The diving board is of uniform cross section and weighs 280 .N

1) Find the force at the support point.

2) Find the force at the end that is held down.

2007-04-22 05:50:15 · 1 answers · asked by ? 1

please help! thanks :)

2007-04-22 05:47:48 · 5 answers · asked by Anonymous

scientifically

2007-04-22 04:58:34 · 3 answers · asked by Kimberly M 1

2007-04-22 04:47:47 · 8 answers · asked by Sparks 2

just wondering.

2007-04-22 04:26:31 · 10 answers · asked by fendi :) 2

I've tried these problems soo many times and my answers are NOT matching up with the answer keys. WIll you do these problems and let me know what you get? I will tell you what I have been getting and maybe you will be able to see what I am doing wrong! Thank you so much for your help!


1. The mass of Earth is about 80 times that of the moon and its radius is about 3.7 times that of the moon. Calculate the acceleration due to gravity at the surface of the moon. Express your answer in g's.
(for this one I got 1.7)


2. Calculate the force of gravity on a 13 kg mass if it were 6.4
*10^6m above Earth's surface (that is, if it were 2 Earth radii from Earth's Center.) The mass of Earth is 6 *10^24

(For this one I got...2.13e29)

3.Calculate the force of gravity between Earth and the sun (Sun's mass = 2.0 *10^30 kg; Earth's mass = 6 *10^24 kg; average Earth-Sun distance = 1.5 *10^11 m).

(For this one I got 0.00592888889)

2007-04-22 04:12:50 · 6 answers · asked by Bella J 1

a 45 W light bulb that has a current of 0.38 A? the current drawn by a 4.0 W flashlight bulb that uses a 12 V battery?

2007-04-22 04:06:22 · 2 answers · asked by Anonymous

Ok, this question was sparked from the Doctor Who book Im reading at the minute 'Only Human'. Basically a Neanderthal is calling humans idoits for not understanding that things change when you look at them, which according to him is obvious. I dont like being called an idiot (especially by a Neanderthal) and so if someone out there can give me bit of an insight and understanding into this I would be very grateful! Just a casual answer not going into too much detail is what Im looking for.

Many thanks!

2007-04-22 03:23:16 · 7 answers · asked by Numptyhead 2

3D is three dimensions, characterized by Cartesian (x - horizontal, y - vertical , z - depth) coordinates. But I read somewhere that without time, the 3rd Dimension would just be like a 3D comic, without life nor movement. Time is the 4th characteristic, they say, but I also read somewhere that there are other aspects of time that makes us live actually in the 5th Dimension. Please, I ain't no cosmonaut, can somebody help explain this, in simple terms, thank you very much.

2007-04-22 02:53:40 · 4 answers · asked by Aekae 2

What are the differences?

2007-04-21 22:07:01 · 2 answers · asked by Anonymous

A rock climber of mass 70.0 kg wears a 12.0 kg knapsack while scaling a cliff. After 30.0 minutes, the climber is 8.20 m above the starting point.
(i) During the 30.0 min climb, what is the climber's average power in kilowatts?
(ii) If the climber drops the knapsack from 8.2 m, determine the velocity of the knapsack at the instant before it strikes the ground at the climber's starting point

2007-04-21 21:48:06 · 1 answers · asked by Amber B 1

From more and more theoretical discoveries in physics, quantum mechanics seems to be showing itself. Any thoughts?

BTW, don't answer if you don't know what I'm talking about.

2007-04-21 20:24:45 · 6 answers · asked by Nick M 2