Physics - March 2007

We're told that before the big bang the universe was condensed into a space so small it's almost unthinkable, so does this small size mean it has super-concentrated gravity, or would the dynamics of size in space still apply(in that the smaller the object in space the less gravity is exhibits)?

2007-03-25 10:10:38 · 7 answers · asked by Luis 6

I can do it without the angle, so can someone show me the steps to do it with the angle?

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle '2 = 42° from the neutron's initial direction. The neutron's initial speed is 5.0 105 m/s. Determine the angle at which the neutron rebounds, '1, measured from its initial direction.

°
What is the speed of the neutron after the collision?

What is the speed of the helium nucleus after the collision?

2007-03-25 10:04:45 · 1 answers · asked by beast 1

Or to measure small distances?

2007-03-25 09:50:49 · 2 answers · asked by xo_That's A Promise_ox 2

You've probably heard the old saying that "anything is possible"....so, exactly how possible is time travel, and what is required to make it possible?

2007-03-25 09:43:48 · 3 answers · asked by Anonymous

A circular disk with a mass m and radius R is mounted at its center, about which it can rotate freely. The disk has moment of inertia I = 1/2 mR^2
A light cord wrapped around it supports a weight mg.
Find the total kinetic energy of the system, when the weight is moving at a speed v. Pick best one:

(all are set equal to K)
1. K = 5/4 mv^2
2. = 3/4 mv^2
3. = 1/3 mv^2
4. = 1/2 mv^2
5. = 2/3 mv^2
6. = mv^2
7. = 3/2 mv^2
8. = 4/5 mv^2
9. = 5/2 mv^2

2007-03-25 09:34:24 · 2 answers · asked by lennox lewis 1

i know there must be some physical law that causes this, but I can't figure it out.

2007-03-25 09:14:37 · 13 answers · asked by annikagyrl 2

I need to know a possible way to do this for a physics project. The lightbulb must be in working condition, and it must be on an active circut that has a current running through it. The lightbulb cannot be broken, and I can't just use a huge resistor, because there would still mathematicly be a small current going through the bulb. Any ideas?

2007-03-25 09:02:24 · 5 answers · asked by Anonymous

i'm trying to pick out what i should ask for my bscience unit next year does anyone recommend anything?

2007-03-25 08:52:13 · 3 answers · asked by kdm_615 2

I have been reading a book called Angels and Demons and there is a part where a scientist has just recetly discoverd "Antimatter". It is highly explosive if it comes in contact with matter ( everything on earth is made of matter). It says that one gram or something can light up New York for a whole week and produces no radiation, no pollution. So is there really such a thing called Anitmatter, if there is then why haven't scientist been using it? is it because it is highly explosive?

2007-03-25 08:46:03 · 11 answers · asked by Alucard 2

An electron accelerated from rest through a voltage of 410 V enters a region of constant magnetic field. If the electron follows a circular path with a radius of 17 cm, what is the magnitude of the magnetic field?

I'm using r = mv/qB and I am trying to find B. I know r, m, and q, but not sure what v would be here.

2007-03-25 08:39:36 · 1 answers · asked by Anonymous

what are different examples of where i should reduce friction and how would you reduce it

2007-03-25 08:37:54 · 3 answers · asked by chris_as24 2

ok seriously no Cpt. Kirk or is it possible...
Please I need a serious answer

2007-03-25 08:17:28 · 1 answers · asked by iSmile 2

"Wot is light made of?"
Dont tell me the actual answer
just tell me wot it answers
for example: it answers the nature of light
Thanks for any help : )

2007-03-25 08:14:44 · 5 answers · asked by ☼Scientific Athletic♫ 4

My book has the answers. Can someone show me the steps?

A tennis ball of mass m = 0.06 kg and speed v = 25 m/s strikes a wall at a 45° angle and rebounds with the same speed at 45° What is the impulse given the wall?

The answer is: Magnitude= 2.1 N*s

2007-03-25 07:59:06 · 3 answers · asked by beast 1

2007-03-25 07:49:17 · 3 answers · asked by Nazim B 1

Using physics, relate a roller coaster, a super bouncy ball, and a pendulum to each other.

Don't you just love science?

2007-03-25 07:47:29 · 6 answers · asked by firesh0t 1

The solar energy coming to the earth by radiation is 1340 W/m^2 when the temperature of the sun is 5800 K. If the temperature of the sun deceased by 10% then what would be the amount of solar radiation coming to the earth?

please help, thanks

2007-03-25 07:45:40 · 1 answers · asked by Anonymous

Not resistance, resitivity.
I only want a value...

2007-03-25 07:40:12 · 3 answers · asked by Mark R 2

A tungsten light bulb is glowing with a blackbody radiation whose maximum occurs at a wavelength of 700 nm. What is the temperature of the tungsten element??

please help, thanks

2007-03-25 07:13:48 · 1 answers · asked by Anonymous

2007-03-25 07:13:25 · 22 answers · asked by jaygee 2

You're on the train and shoot forward, what happens?

You shoot behind, what happens?

2007-03-25 07:12:37 · 4 answers · asked by OE "800" 3

I've been reading and thinking about time travel a lot lately. I'm pretty sure it's impossible, at least time travel to the past. Here's my (dis)proof:

All of the variables below are vectors. This means that they are an amount and a direction. For example, if you're going to define a positive velocity as traveling North, then a negative velocity would be traveling South (the opposite direction).

It's a fact that Velocity = change in distance / Change in time

Let's solve this equation for time.

v = d/t
tv = d (cross multiplication)
tv/v = d/v
t = d/v

Now, I want the time to be negative, to signify a negative change in time, or... reversing time.

-t = -d/v

What this equation is saying is that in order for time to go backwards, distance and velocity need to be going in opposite directions.

For example:

Imagine going 30 mph North, but you're actually moving South. Makes no sense? Exactly.

2007-03-25 06:54:07 · 5 answers · asked by rickpetralia 1

2007-03-25 06:52:44 · 3 answers · asked by dr_ardalan_uk 1

and what 5 objects have the same speed but different velocity

2007-03-25 06:48:10 · 13 answers · asked by Anonymous

2007-03-25 06:44:16 · 1 answers · asked by Anonymous

Feyman used space-time diagrams to show that there is only one electron!

Is this an accepted theory by the world?
Can it be proved or disproved?

2007-03-25 06:33:41 · 3 answers · asked by sh 1

Water falls a distance of 50 meters. The specific heat of water is 1.0 cal/gm C. What is the increase in temperature of the water after the fall in degree C??

please help, thanks

2007-03-25 06:30:08 · 2 answers · asked by Anonymous

It's for my written report on my science project.

2007-03-25 06:19:47 · 6 answers · asked by PRiNCESS~KAiii 1

1. What effect does doubling the length of the pendulum cord have on its period?

2. What effect does reducing the length of the pedulum cord by one-helf have on its period?

3.Determine the length of pendulum cord needed in order to result in a period (T) of precisely 5 seconds.

2007-03-25 06:08:41 · 2 answers · asked by Anonymous

Jaclyn in on an elevator before it begins to move. She pulls out her handy newton force scale and attaches it to the ceiling of the elevator. Next she hangs her 10 kg bag on the scale and notes a reading of 98N, while at rest. When the elevator begins to move the scale suddenly reads 95N. Find and explain the magnitude and direction of the acceleration of the elevator.

2007-03-25 06:06:46 · 2 answers · asked by Anonymous