Physics - December 2007

it's possible in theory, but is it possible in fact? if so what is it thats in perpetual motion on the earth?

2007-12-10 13:59:19 · 6 answers · asked by Anonymous

i dont understand any science what so ever!

2007-12-10 13:58:29 · 5 answers · asked by cArL 1

ok how can m-theory be established if all 5 string theories have such a diffrent behavior and apperance of strings.for example type I have closed and open loops, but type IIA and IIB have open string that are attached to D-Brane. i also have a question about the 11th dimension

2007-12-10 13:55:52 · 3 answers · asked by Anonymous

A playground merry-go-round of radius 2.00 m has a moment of inertia I = 335 kg·m2 and is rotating about a frictionless vertical axle. As a child of mass 25.0 kg stands at a distance of 1.00 m from the axle, the system (merry-go-round and child) rotates at the rate of 11.0 rev/min. The child then proceeds to walk toward the edge of the merry-go-round. What is the angular speed of the system when the child reaches the edge?

2007-12-10 13:35:48 · 2 answers · asked by Brittany F 2

I was wondering if brain waves were like sound waves. If so could someone record there voice for like a door lock then put on a brain wave amplifier and be able to unlock the door with his/her mind by just saying what the recorded words. Because I would like to try it but do not have the funds. What do you answerers think?

2007-12-10 13:29:47 · 7 answers · asked by encikus 2

2007-12-10 12:59:17 · 3 answers · asked by Poonani 1

Use the data of Table 7.3 to find the point between Pluto and the Sun at which an object can be placed so that the net gravitational force exerted by Pluto and the Sun on this object is zero. Answer is m from center of Pluto.
Data from table:
Pluto's radius = 1.5e6
Pluto's distance from the sun = 5.91e12
Sun's radius = 6.96e8

Info from notes:
G = 6.67e11
F=G(m1m2/r^2)

I'm assuming you use this equation and set the two sides equal, but I can't get it to work. Thanks in advance!

2007-12-10 12:58:39 · 1 answers · asked by Anonymous

why can't we harness electricity from lightning?
In some place that is known for lightning why can't we put up a huge pole. Either for the lightning to hit. Or maybe it could be raised into the clouds. Where the positive and negative charges are. then we could use that charge for electricity.

Now it won't be a constant supply. But neither is wind.

2007-12-10 12:34:26 · 8 answers · asked by Philip Augustus 3

During spring semester at MIT, residents of the parallel buildings of the East Campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. A balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. Assume that the stretching of the hose obeys Hooke's law with a spring constant of 112 N/m. If the hose is stretched by 4.50 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length?

2007-12-10 12:29:41 · 1 answers · asked by Anonymous

You push a 1.9 kg block against a horizontal spring, compressing the spring by 16 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 80 cm from where you released it. The spring constant is 200 N/m. What is the block-table coefficient of kinetic friction?

2007-12-10 12:26:42 · 1 answers · asked by Anonymous

answer in g/cm3

2007-12-10 12:07:53 · 1 answers · asked by Anonymous

Okay, so in my science class, we're studying waves.

Ex. Mechanical waves, electromagnetic waves, transverse waves, etc...

My group conducted experiments with a slinky (did I spell that correctly?) and we're suppose to demonstrate amplitude, compression, and constructive interference.

What type of wave is it when the slinky slides up and down along the floor? Sine wave, cosine wave, or does it depend on the way we move it?

I know that cosine waves start off with the crest at the y-axis, but I'm not quite sure of it in the real world.... Can't really explain how I don't understand xD!

And this is just something that came up on my interest, but how do I find the amplitude of the following?

y = sin x + 2sin 2x
y = sin 3x + cos 4x
y = cos 6x + cos x

Do I have to use identities?

Thanks.

2007-12-10 11:40:43 · 3 answers · asked by UnknownD 6

at t=0 a .755kg mass at rest on the end of a horizontal spring (k=124N/m) is struck by a hammer which gives the mass an inital speed of 2.96m/s determine the postion as a function of time and find the total energy

2007-12-10 11:37:06 · 1 answers · asked by Erin S 1

The smallest constant force that must be applied to stop it in 20 seconds is?

2007-12-10 11:33:23 · 3 answers · asked by Anonymous

Question One ---. A 0.024 kg ball is dropped to the floor from a height of 1.75 meters. Just after the impact with the floor, the ball has an upward velocity of 5.2 m/s. If the ball was in contact with the floor for exactly 0.023 seconds, find the following:

a.) The impulse delivered to the ball, from the floor.
b.) The average force of impact.

Question TWO --- Two identical objects A and B of mass 4.0 kg move on a horizontal and frictionless surface. Object B initially move to the right with a speed of 0.5 m/s. Object A initially moves to the right with the speed of 1.5 m/s, so that it collides with object B.

a.) Determine the total momentum of teh two cart system.
b.) A student predicts that the collision will be totally inelastic (they stick together after the collision). Assuming this is true, determine the velocity of each object immediatly after the collision.

PLEASE HELP
YOUR HELP IS GREATLY APPRECIATED!!!!

2007-12-10 11:22:38 · 1 answers · asked by mimi j 1

What happens to the brightness, voltage and current of the bulbs as more bulbs are added in parallel? Why?

2007-12-10 11:20:08 · 3 answers · asked by sunita s 1

Alright here is my problem, a 5.00 kg block is moving at 5.00 m/s along a horizontal frictionless surface toward an ideal spring that is attached to a wall. After the block collides with the spring, the spring is compressed a maximum distance of 0.68m. What is the speed of the block when the spring is compressed to only one-half of the maximum distance?

2007-12-10 11:02:18 · 3 answers · asked by meeko 2

A rubber ball of mass 0.2 kg is released from an upstairs window of a building and strikes the ground at a velocity of 30 m/s. The ball bounces upward from the ground at a speed of 20 m/s. What is the impulse for the time the ball is in contact with the ground (in N s)?

Thank you!

2007-12-10 10:52:06 · 2 answers · asked by carrerasarah 2

A vertical spring (ignore its mass), whose spring stiffness constant is 950 N/m, is attached to a table and is compressed down 0.150m. (a) an upward speed can it give to a 0.30 kg ball when released? (b) How high above its original position (spring compressed) will the ball fly?

2007-12-10 10:26:25 · 3 answers · asked by ____ 3

Ok so basically, there is a diagonal arrow indicating a downward push on a 75kg box. This arrow represents 50N and forms a 30 degree angle with the box (under the arrow). How do i find Fn and the horizontal + vertical ocmponents given this information. Please help!

BY THE WAY: FRICTION IS NEGLIGIBLE IN THIS PROBLEM!

2007-12-10 10:20:07 · 1 answers · asked by kerwin 1

Please.
Anything will help.
Thankyou

2007-12-10 10:16:20 · 2 answers · asked by Anonymous

At a picnic, a Styrofoam cup contains lemonade and ice at 0°C. The thickness of the cup is 2.0 10-3 m, and the area is 0.016 m2. The temperature at the outside surface of the cup is 34°C. The latent heat of fusion for ice is 3.35 105 J/kg. What mass of ice melts in 1 hour?

2007-12-10 10:16:04 · 1 answers · asked by Britt 3

just curious

2007-12-10 09:52:51 · 2 answers · asked by I want to delete my answers account 3

Gravity pulls at an object at 16 ft/sec.
If I throw an object vertically, as in straight up into the air with no curve at all, gravity will pull on it at 16 ft/sec

But if I throw an object in an arc, or in between a vertical and horizontal path, shouldn't gravity pull on it at 8ft/sec?

2007-12-10 09:39:58 · 3 answers · asked by Anonymous

if an sphere is falling at max speed and it suddenly splits into two perfect halfs. the cut is in a perfect place so that the wind resistance stays the same as if it was whole. will the sphere slow down increase sped or do anything at all

2007-12-10 09:23:34 · 4 answers · asked by Bookworm 1

The 911s have the engine sitting behind the rear axle, which results in a big REAR-WARD weight bias. My theory was always that - since 'inertia' is always proportional to mass, the rear end had higher inertia than the front end, and thus the rear end tends to want to move in a straight line tangential to the curve so it leaves the curve first.... i.e. the centrifugal force, so to speak....

2007-12-10 08:55:11 · 1 answers · asked by Anonymous

2007-12-10 08:54:14 · 9 answers · asked by Anonymous

2007-12-10 08:51:32 · 11 answers · asked by Imperial 2

how do you do it

2007-12-10 08:36:48 · 8 answers · asked by Adam S 1

I said refraction and looked like a ****in idiot!

2007-12-10 08:35:28 · 4 answers · asked by Anonymous