Physics - December 2007

If a certain sample of an ideal gas has a temperature of 104 degrees C and exerts a pressure of 2.3 x 10^4 Pa on the walls of it's container, how many gas molecules are present in each cm^3 of volume? assume that the gas is ideal. The gas constant is R=8.314 J/mol K and avagadro's number is NA=6.022 x 10^23 molecules/mol

???

2007-12-11 09:17:14 · 6 answers · asked by Statia B 1

I am confused with this HW assignment:

The entropy of a system is found by placing a sign -in front of sign Σ in front of products of thingies P_i and their logarithms. Using letter S for entropy and denoting logarithms by ln() write an expression for the entropy of the system.

I figured out that the beginnig should look like
S = -Σ
but logarithms took me completely off guard. What are those logarithms things anyway.

I need to know, because I am finishing my MS in physics and plan to develop tubines for airplane engines.

2007-12-11 09:13:45 · 4 answers · asked by Alexander 6

i know if it were fired straight up the trajectory would be 0 meters/sec but i have NO clue how to figure out the speed at the top of trajectory would be if its fired at an angle.

explain please!!

2007-12-11 08:56:35 · 2 answers · asked by sharpieharpie 1

At t = 0, a 715 g mass at rest on the end of a horizontal spring (k = 127 N/m) is struck by a hammer, which gives it an initial speed of 2.77 m/s.
1. Determine the period of the motion in seconds.
Determine the frequency of the motion.

2. Determine the amplitude.

3. Determine the maximum acceleration.

4. Determine the position as a function of time.
( ____ m ) sin[ ( _____ rad/s)t ]

5. Determine the total energy.

Any help regarding any of these numbers will be greatly appreciated. Please show all work. First person to get all answered correctly gets best answer. Thank you =).

2007-12-11 08:48:40 · 1 answers · asked by Anonymous

http://answers.yahoo.com/question/index?qid=20071211132536AALgPBt

I thought that kinetic energy, and conservqation of mechanical energy is derived by integeraton of dynamic eqautions, but apparently there are new simplified approaches in modern teaching

2007-12-11 08:34:08 · 1 answers · asked by Alexander 6

A satellite is put into orbit at an altitude of 3x10^7 m above the ground. How fast will the satellite be moving? How do you figure out this problem?

2007-12-11 08:31:33 · 4 answers · asked by Kayla B 1

I've been trying for about 2 weeks. Cannot get the answer. Pleae help if you can. thanks

A long horizontal wire carries a current of 48 A. A second wire, made of 2.5-mm-diameter copper wire and parallel to the first, is kept in suspension magnetically 15 cm below. See the figure below. (a) Determine the magnitude and direction of the current in the lower wire. (b) Is the lower wire in stable equilibrium? (c) Repeat parts (a) and (b) if the second wire is suspended 15 cm above the first due to the latter’s field.

2007-12-11 08:26:09 · 1 answers · asked by vkaar 2

He is impressed with intelligent conversation, and I really need to know how do I impress him when i know nothing about physics!! Tell me something cool I can discuss with him related to physics.

2007-12-11 07:54:56 · 7 answers · asked by tickertock 3

the curve y(1)= [1 / (x+1) ]^n (

is reflected through the y-axis to form curve y(2) so that y(1) and its mirror image y(2) form a cusp at x=0.

curve y(2) is translated to the right a distance d to form curve y(3)
curve y(1) is translated to the right a distance d to form curve y(4)
so that y(3) and its mirror image y(4) form a cusp at x = d.

Let F = intgegral of the product, y(1)*y(3).dx over the interval 0 < x < d

Let G = integral of the product, y(1)*y(4).dx over the interval d < x < infinity

what is the value of d when F=2*G if n=1?
what is the value of d when F=2*G if n=2?
in general?

show how you got your answer.

2007-12-11 07:38:37 · 1 answers · asked by Anonymous

I do not need answers I just need some direction here.

A particle of mass m slides without friction on a track. AB is a straight section. BCD is a circular section of radius R. The particle starts from rest at A and leaves the track at point D. [Neglect air resistance].

(a) what force of constraint does the track exert on m at point D just before m leaves the track?

(b) how high does m rise above the ground after it leaves the track?

http:\\www.geocities.com\trunks11111\final1.jpg

2007-12-11 07:20:10 · 2 answers · asked by Nate-dawg 2

2007-12-11 07:02:11 · 2 answers · asked by Erica Marie 1

1.convert 0.50 kilometers into meters
a. 0.0050 m
b. 50 m
c. 5.0 x 10² m
d. 5.0 x 10³ m

2. express this measurement in standard scientific notation: 501 000
a. 501 x 10 ³
b. 5.01000 x 10 ⁵
c. 5.01 x 10 ⁵
d. 0.501 x 10 ⁶

3. a student measures a length to be 3.4 cm, then 3.4 cm again. the ability of the student to reproduce the measurement exactly shows he has very good:
a. accuracy
b. extrapolation
c. precision
d. interpolation

4. the number of significant digits in the measurement 60.080 kg is:
a. 2
b. 3
c. 4
d. 5

5. which of the following measurements contains zeros that are not significant?
a. 3.050 x 10⁵ mm
b. 0.0053 m
c.45.020 cm
d. 101 g

2007-12-11 06:38:51 · 4 answers · asked by Anonymous

A. moderator
B. coolant
C. control rod
D. critical mass

2007-12-11 05:55:09 · 3 answers · asked by cofeavloit 1

The radius of the girth of the planet is a=1000km, and the larger radius c of the donut itself is unknown, but very large c>>a. I use notation a and c as can be seen here:
http://mathworld.wolfram.com/Torus.html

Due to global warming the temperature of the atmosphere is gradually increasing. At what temperature will the atmosphere completely 'evaporate' and dissapear?

The acceleration of gravity on the surface is g=1m/s².

2007-12-11 05:52:34 · 4 answers · asked by Anonymous

a 60kg bungee jumper jumps from the same height as the fixed end of a 10m bugee cord of ks = 200N/m. If g = 10m/s^2 what is the maximum extension of the cord.

Assume cord obeys hookes law, ignoring friction and air resistance. And considering the energy of the system: person + cord.

The answer is 11.3m but I'm having trouble getting it.

2007-12-11 05:47:53 · 3 answers · asked by eazylee369 4

answer in units of kgm^2/s

2007-12-11 05:42:07 · 2 answers · asked by ms. nelz09 1

I was told humid air is less dense than hot dry air. Why is this? I thought the heat would make the gas disperse and therefore less dense, and that saturating it with water would cause greater density than not having anything in it at all.

2007-12-11 05:36:44 · 5 answers · asked by Anonymous

In order to produce a "true vacuum", we would have to be able to not only remove all matter from the chamber, but insulate it against any and all forces - heat (we would technically have to insulate the inner layer of "hull" so it wouldn't radiate any heat transfer), electricity, magnetism, gravity...

Any hope of insulating against gravity is far beyond our reach at this point, and I suspect magnetic dampers are either beyond reach or impractical. But we can certainly insulate against some of the other things.

Is there any known way to confine a space, remove the matter (most if not all) and squelch the electromagnetic passthrough either completely or just to a significant degree?

A secondary question: Would this space have any unusual properties -other- than being a near-perfect vacuum?

2007-12-11 05:30:01 · 5 answers · asked by uncleclover 5

A weight of 600.0 N is raised 4.65 m by a pulley system which has an IMA of 3.00.
How far must the effort travel to accomplish this?
What effort is required to maintain dynamic equilibrium if friction is neglected?

Effort Distance = ________________ m

Effort Force = ________________ N

2007-12-11 05:19:53 · 1 answers · asked by Anonymous

is it
aufbau principle, hunds rule, paulis exclusion principle , periodic law or heisenbergs priciple

2007-12-11 05:04:18 · 1 answers · asked by HisGlory 1

Consider a smooth incline plane 9 m long rising to a height of 2.7 m. Calculate the largest load that can be moved up along the plane by an input force of 600 N applied parallel to the plane.

load = ___________ N

2007-12-11 05:02:27 · 4 answers · asked by Anonymous

just kinda thinking about possibilities @ the moment.. thinking about rapid prototyping with ice... dunno.. fun to think about.

2007-12-11 04:52:31 · 1 answers · asked by bandaidsrcool 2

A steam engine has a boiler that operates at 500K. The energy from the boiler changes water to steam, which drives the piston. THe temperature of the exhaust is that of the outside air, 300K. You may assume an ideal engine.
a) what is the engine's efficiency?
b) If 3.5E3 J of energy is delivered to the engine (QH) during one cycle, find the work done by the engine.

2007-12-11 03:42:40 · 1 answers · asked by rachhar123 1

A system of monatomic ideal gas starts at a pressure of 1.0E5 Pa, a volume of 5.0E-3m and an initial temperature of 300K. Gas is confined to cylinder by a movable piston. Gas slowly expands at constant volume to pressure of 3.0E5Pa. This is point B. Next it undergoes an isothermal compression to point C. At point C the pressure is 1.0E5Pa. Finally gas is compressed isobarically until it returns to its original conditions of temperature, pressure and volume.
a) Draw the PV diagram
b) find the # of moles of gas
c) Find the Temperature at B
d) Find the change in internal energy (U), Q & W (work) for isobaric process
e) find the change in U, Q &W for isochoric process
f) find net change in internal energy for entire cycle
g) Is work done on or by the gas? Explain

2007-12-11 03:40:16 · 2 answers · asked by rachhar123 1

I am trying to find as much information on experiments with magnetic monopoles and magnetic currents as possible.

I already know about the experiments described
in charter 5 of http://www.scribd.com/doc/4445/quaternionic-electrodynamics

2007-12-11 03:05:23 · 2 answers · asked by aeiwimaster 1

So the force on a charged particle in a magnetic field is the cross product of the velocity of the particle's velocity and the direction of the field. What I am wondering about is why the "right-hand" rule works, and not the "left-hand" rule. What is the fundamental principle that causes a positively charged particle to travel to the left instead of the right or vice versa?

2007-12-11 02:50:14 · 4 answers · asked by socplayer8 2

electrostatics

2007-12-11 02:22:00 · 2 answers · asked by don 2

electrostatics

2007-12-11 02:19:55 · 1 answers · asked by don 2

the height from the top of the table to the ceiling is 2.54 m. Show all calculations.

I would be so grateful if somebody could explain this to me. thanks.

2007-12-11 02:13:18 · 4 answers · asked by Nomo 2

2007-12-11 02:00:13 · 15 answers · asked by Thor S 1