Physics - February 2007

A certain kind of glass has an index of refraction of 1.650 for blue light of wavelength 430 nm. and an index of 1.615 for red light of wavelenth 680nm. IF a beam containing these two colors is incident at an angle of 30 deg. on a piece of this glass, what is the angle between the two beams inside the glass?

2007-02-26 13:08:12 · 3 answers · asked by Kitana 2

2007-02-26 13:05:55 · 1 answers · asked by Anonymous

Neutrons are negitively charged?

Equal number of protons and electrons the atom is neutral?

The accumulation of electric charges on an object is called magnetism?

The electric field caused by an electron is weakest near the electron.

An electric field becomes weaker as distance from the electron increases?

A conductor is a material that allows electrons to flow through is EASILY?

Metals are poor conductors of electricity?

plastics, rubber, wood and glass are good conductors?

Earth serves as a conductor of electricity?

The presence of electric charges can be detected with an electroscope?

The leaves of an electroscope hang straight down whent he device receives a charge?

If both leaves of an electroscope receives a negitive charge, the leaves will attract each other?

When an object loses electrons, it gains a negitive charge?

if it is wrong, tell me why ? :)

THANKS! :]

2007-02-26 13:03:32 · 5 answers · asked by luckyplaya23 2

Please help! I am learning about lever systems...the question is
What is the theoretical mechanical advantage for a third class lever?
I am looking for a SPECIFIC number, not just an explanation.


Here is a picture of the third type of lever incase you don't know what I am talking about-

http://www.sciencebyjones.com/third_class_levers.htm

ps. My teacher told us that the theoretical mechanical advantage for type 1 is '1' and for type 2 it is '2'...and now we had to figure out what it is for 3 but she never taught us how!!

2007-02-26 12:45:23 · 1 answers · asked by Jane A 3

2007-02-26 12:38:22 · 1 answers · asked by Borat 1

If you could travel at light speed wouldn't you crash into something? I once thought perhaps if you traveled at light speed instead of physical matter colliding it would pass through each other. I also thought maybe the friction of the vacuum of space would create a wall to how fast we can travel through space. Do you think we will ever live in the world of Star Wars or Star Trek and travel at or beyond speeds of light?

2007-02-26 12:38:21 · 4 answers · asked by Anonymous

Acoustic Physics

2007-02-26 12:37:12 · 6 answers · asked by ngs928 1

This is in connection with the gravitational force.

2007-02-26 12:37:09 · 1 answers · asked by mavelle13 1

Could someone guide me as to what this questions answer may be? thanks =)

" Your parent demands that you clean your room. You know that reducing the disorder of your room will reduce its entropy, but the entropy of the universe cannot be decreased. Using one or more sentances, evaluate how you increase entropy as you clean."

Even hints are appreciated...anything that you can give, Thankies ^^.

2007-02-26 12:33:52 · 3 answers · asked by Joann 1

2007-02-26 12:27:32 · 8 answers · asked by Anonymous

A 155 kg horizontal beam is supported at each end. A 290 kg piano rests a fifth of the way from one end.
What is the vertical force on the support closest to the piano?

What is the vertical force on the support furthest from the piano?

2007-02-26 11:58:17 · 2 answers · asked by Anderson W 1

ok im only given intial speed so im not sure how to solve this....

a hockey player fives a speed 1.9 m/s to puck. this is inadequate b/c kinetic friction. as result puck goes 1/2 distance between players before stopping. what is minimum initial speed taht should have been given to puck that that is would have reached teammate???

i dont even know where to begin with this problem... please explain.... in detail

2007-02-26 11:56:29 · 1 answers · asked by Anonymous

2007-02-26 11:51:32 · 6 answers · asked by Jerry B 1

2007-02-26 11:50:29 · 1 answers · asked by Anonymous

A 75 kg adult sits at one end of a 11.0 m board, on the other end of which sits his 25 kg child. Where should the pivot be placed so the board (ignore its mass) is balanced?

2007-02-26 11:45:05 · 4 answers · asked by Anderson W 1

Okay, im doing a science project for school, my topic was on hot water freezing faster than cold water but when i did the experiment the cold water froze faster can you tell me why this would happen?

2007-02-26 11:37:49 · 3 answers · asked by carolyn 3

2007-02-26 11:33:45 · 1 answers · asked by Anonymous

2007-02-26 11:07:19 · 14 answers · asked by Ronaldo V 1

An air filled balloon will float very high on the water. A weight tied to it will make it float lower or even make in sink. Suppose you attach a weight to an air filled balloon that puts it at the verge of sinking - that is the overall density of the weight and balloon is equal to that of the water and its top surface just touches the water line. Now, if you push the balloon beneath the surface of the water what will the balloon do? Explain.

2007-02-26 11:02:21 · 2 answers · asked by jonoco 1

Two electrons in an atom are seperated by 1.5 x 10^-10 m the typical size of an atom. What is the electrical force between them?

2007-02-26 11:01:01 · 1 answers · asked by grouchy187 2

2007-02-26 10:52:52 · 3 answers · asked by Joa 2

Two crates, of mass m1 = 70 kg and m2 = 110 kg, are in contact and at rest on a horizontal surface (Fig. 4-54). A 620 N force is exerted on the 70 kg crate. The coefficient of kinetic friction is 0.15.

Figure 4-54

(a) Calculate the acceleration of the system.
m/s2 (to the right)
(b) Calculate the force that each crate exerts on the other.
N
(c) Repeat with the crates reversed. acceleration m/s2
crate force N

2007-02-26 10:49:30 · 1 answers · asked by nafiseh g 1

2007-02-26 10:44:39 · 10 answers · asked by PETE 1

'Little boy' was a Uranium bomb which exploded with a force equal to 13,000 tones of TNT and killed 70,000-130,000 people immediately.
'Fat man, on the other hand exploded with a force equal to 20 kilo tonnes of TNT but killed only 45,000 people immediately. If fat man was more powerful, why did it kill less people?

2007-02-26 10:36:00 · 9 answers · asked by mallybb298 3

Which ball (a small golf ball or a bigger ball made out of rubber) would have the bigger velocity when rolled down a hill and why?

2007-02-26 10:34:17 · 1 answers · asked by venus 1

The two blocks are connected by a light string that passes over a frictionless pulley with a negligible mass. The 3 kg block lies on a rough horizontal surface with a constant coefficient of kinetic friction 0.3. The hanging block has a mass of 8 kg.The system starts from rest.The acceleration of gravity is 9.8 m/s2 :
What is the speed of the 8 kg hanging mass when it has fallen a height 8 m? Answer in units of m/s.

2007-02-26 10:31:53 · 1 answers · asked by kavita 1

2007-02-26 10:30:40 · 2 answers · asked by carmen e 1

Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.70×106 , one at an angle 19.0 degrees west of north, and the other at an angle 19.0 degrees east of north, as they pull the tanker a distance 0.600 toward the north.

What is the total work done by the two tugboats on the supertanker?

2007-02-26 10:28:20 · 1 answers · asked by Anonymous

A uniform electric field is directed upward and has a magnitude of 2 N/C. What are the magnitude and direction of the force on a charge of -3 C placed in this field?
N

2007-02-26 10:18:14 · 1 answers · asked by bibun 2

A test charge of +9 10-6 C experiences a downward electrostatic force of 15 N when placed at a certain point in space. What are the magnitude and direction of the electric field at this point?
N/C

2007-02-26 10:17:41 · 1 answers · asked by bibun 2