Physics - February 2007

I know it's really simple, but I'm having some trouble understanding the concept of vapor pressure. Could I get a quick overview or definition? Thanks.

2007-02-21 12:38:10 · 6 answers · asked by The Ghetto David Hume 3

Three pieces of string, each of length L, are joined together end-to-end, to make a combined string of length 3L. The first piece of string has mass per unit length u1(mu subscript 1), the second piece has mass per unit length u2 = nu1, and the third piece has mass per unit length u3 = u1/n.

If the combined string is under tension F, how much time does it take a transverse wave to travel the entire length 3L? Give your answer in terms of L, F, and u1.

Conceptual questions are my weakness! Can someone help me out with this one?

2007-02-21 12:14:50 · 1 answers · asked by Anonymous

i weight about 155 pounds

2007-02-21 12:06:21 · 5 answers · asked by Greg P 1

usally look like a huge puffyball with a ring around it ( im mostly wondering about the ring) does it have anything to do with it or is it just a conisedence?

2007-02-21 12:05:49 · 2 answers · asked by madame94 2

A carnot engine performs work at the rate of 440 kW while using 680 kcal of heat per second. If the temperature of the heat source is 570 C, at what temperature is the waste heat exhausted? Any help would be great, thanks!

2007-02-21 11:57:35 · 2 answers · asked by Wael K 2

Can you help me?
Transformation in the real world.
a) Where do you see examples of translation?
b) Where do you see examples of reflection?
c) How are these transformations alike?
d) How can coordinate grids be used to illustrate these differences and similarities?

For a)
I know elevator, conveyor belt
For b)
I knoe mirror, lake
For c)
I know they are congruent
For d)
I didn't get it

I need you answers. Please help me. I know I don't have all the answers. What do you think?
Help!!!

2007-02-21 11:47:53 · 1 answers · asked by Anonymous

True or False....Frequencies of transitions between corresponding stationary states in hydrogen, deuterium, and tritium are identical.

And

Frequency of characteristic X-rays for elements depend on: (Atomic weight or Atomic Number?)

Any help is appreciated.

2007-02-21 11:46:28 · 1 answers · asked by PhyzicsOfHockey 2

i am screwed for my physics test

2007-02-21 11:41:28 · 4 answers · asked by Anonymous

2007-02-21 11:32:15 · 2 answers · asked by Anonymous

The Royal Gorge bridge over the Arkansas
River is 372 m above the river. A bungee
jumper of mass 110 kg has an elastic cord of
length 79 m attached to her feet. Assume the
cord acts like a spring of force constant k. The
jumper leaps, barely touches the water, and
after numerous ups and downs comes to rest
at a height h above the water.
The acceleration of gravity is 9:81 m=s2 :
Find h. Answer in units of m.
part2
Find the maximum speed of the jumper. An-
swer in units of m=s.

2007-02-21 11:30:49 · 2 answers · asked by kavita 1

the picture looks exactly like a nomal sunset, but the semi-circle that is the actual sun is flipped across the horizon. Other than this it is an ordinary sunset. I was wondering if there was an explanation of this regarding physics (a cloud is acting as a lens, ect.) I know that this is not from reflection as the water is not smooth, but the image of the half-sun on the water is almost a perfect solid semi-circle

2007-02-21 11:25:35 · 2 answers · asked by Anonymous

When a bullet traveling at 739 m/s strikes a block of wood originally at rest on a frictionless surface, the bullet emerges from the other side of the block of wood traveling at 397 m/s. If the mass of the bullet is 4.79 g and the mass of the block is 715 g, what is the speed of the block after the collision?

2007-02-21 11:19:11 · 3 answers · asked by N 1

My science teacher had a plastic, vertical stress device that was closed and sperical on the top and on the bottom, with the spheres connected by mostly vertical cylindrical shaped tubes. On the bottom sphere, there was a red-looking liquid (possibly mercury) while the top sphere would still be empty. To find out if a person were stressed, the person would put their hand where the bottom sphere was, holding the object right-side up. If this person were stressed, the red-liquid would shoot up to the top sphere, through the tubes, and instead of filling the top sphere up with liquid, would start to boil. What is this device and where I can get it? (It would help to provide a link to the store.)

2007-02-21 11:09:26 · 1 answers · asked by pnogal32 2

Can someone explain what it is in words i can understand

2007-02-21 11:07:20 · 2 answers · asked by Charlotte 2

Magicians often make objects disappear by using trick mirrors. How might a magician seem to make an object disappear by using a concave mirror?

2007-02-21 11:06:55 · 1 answers · asked by thedogman b 1

2007-02-21 11:04:55 · 5 answers · asked by Amanda Thomas 1

what was the acceleration and the speed when making the tackle?

2007-02-21 10:47:46 · 3 answers · asked by sweetnightmare 1

a bullet is fired straight up with an initial velocity of 250 meters per second. (a) by setting the motion equation equal to zero, find how long it takes for the bullet to have a vertical velocity of zero. (b) using the time found from part (a), find the maximum height the bullet reaches.

2007-02-21 10:47:38 · 1 answers · asked by mandy 1

A 700 kg Toyota collides into the rear end of a 2400 kg Cadillac stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 5.0 m before stopping. The police officer, knowing that the coefficient of kinetic friction between tires and road is 0.40, calculates the speed of the Toyota at impact. What was that speed?

2007-02-21 10:44:11 · 1 answers · asked by Eddie G 1

a block that has a mass of 24 kg is initially at rest on an inclined plane. (a) find the component of the weight that is parallel to the plane. (b) find the component of the weight that is perpendicular to the plane. (c) find the maximum force of static friction if the coefficient of static friction is .65. will the block slide down the plane?

2007-02-21 10:42:25 · 1 answers · asked by mandy 1

If you can, tell how each plastic looks like.

2007-02-21 10:41:03 · 1 answers · asked by Anonymous

using newton's law of gravitation, find the force that the earth exerts on the moon. also, find the force the moon exerts on the earth. useful numbers: m (subscript) earth = 5.98 x 10^24 kg; m (subscript) moon = 7.36 x 10^22 kg; distance from the center of the earth to the center of the moon = .38 x 10^9 meters; G = 6.67 x 10^-11 N * m^2 * kg^-2.

2007-02-21 10:39:25 · 2 answers · asked by mandy 1

a .2 kg ball was released from a height of 12 meters. the ball hit the ground and rebounded to a height of 9 meters. (a) what was the vertical velocity of the ball just before it hit the ground? (b) what was the vertical velocity of the ball when it hit the ground? (c) the collision with the ground was inelastic because kinetic energy was lost. how much energy was lost to heat and sound in the collision with the ground?

2007-02-21 10:32:58 · 2 answers · asked by mandy 1

Does the acceleration of a freely falling object depend to any extent on the location, -- that is, whether the object is on top of Mt. Everest or in Death Valley, California?

2007-02-21 10:28:48 · 7 answers · asked by Esther 1

to the space-time we experience in this reality?

2007-02-21 10:11:05 · 1 answers · asked by k forrest 2

I am having trouble with this question, I know the answer is
5.4 *10^-5 but I don't know how to go about finding the answer:

A 45 kg traffic light is suspended form 2 steel cables of equal length and radii of 0.005 m. If each cable makes a 15 degree angel with the horizontal, what is the fractional increase in their length due to the weight of the light?

If someone can please help explain the proceedure to finding the solution, it would most apreciated

2007-02-21 09:41:43 · 1 answers · asked by mksbema 1

I'm having problems with an online homework problem for my Phys II class. When I try to type what I get as a response, I get a notice that says my answer is off by 10%.
The question is:
*************************************************************
The quantity of charge q (in coulombs) that has passed through a surface of area 1.92 cm^2 varies with time according to the equation q = 4t^3 + 5t + 6, where t is in seconds.

(a) What is the instantaneous current through the surface at t = 0.92 s?

(b) What is the value of the current density?
______ kA/m2
**********************************************************
I know the equations for the problem, but when I substitute the numbers, i don't get the right answer.
Can somebody give me a short explanation?
I would really appreciate it.

2007-02-21 09:35:14 · 4 answers · asked by Jess 2

The question was something like that I'm not sure and also if you through a ball straight up and its at the top were its velocity is 0 is its acceleration 0 also??

2007-02-21 09:08:46 · 7 answers · asked by Anonymous

2007-02-21 09:08:03 · 4 answers · asked by silent1 4

An astronaut on the planet Zircon tosses a rock horizontally with a speed of 6.35 m/s. The rock falls through a vertical distance of 1.40 m and lands a horizontal distance of 8.55 m from the astronaut. What is the size of the acceleration due to gravity on Zircon?

2007-02-21 08:29:03 · 6 answers · asked by soccerjock 2