Physics - February 2007

(Polystyrene or thermocol)

2007-02-01 17:38:35 · 3 answers · asked by deostroll 3

I'm having a horrible time trying to figure this out...Derive a relationship for the height of a given pressure surface (p) n terms of the pressure p0 and temperature t0 at sea level, assuming that temperature decreases uniformly with height at a rate Γ Kkm-1. I have formulas but can't seem to put them together to get what I need...

2007-02-01 17:31:47 · 3 answers · asked by A-train 1

What is an ellipse? What does it mean when an ellipse is in a perfect circle? What causes a black hole?

2007-02-01 17:29:33 · 2 answers · asked by Sally 2

I am struggling with this question and can't arrive at an answer. Any detailed guidance/help anyone could give would be greatly appreciated.

A light bulb is wired in series with a 132 ohm resistor, and they are connected across a 138.0 V source. The power delivered to the light bulb is 22.7 W. What are the two possible resistances of the light bulb?

lower value= ?
higher value= ?

I know that V=IR and P=IV and that my equivalent resistance is going to be R= 132 +x but past that I'm lost.

2007-02-01 17:19:14 · 2 answers · asked by larkinfan11 3

2007-02-01 17:14:52 · 4 answers · asked by Anonymous

In other words, if I had an infrared camera or binoculars, would I be able to see through clouds? I refer to water droplet clouds, not dust clouds. Thank you.

2007-02-01 16:53:07 · 1 answers · asked by Javachip 1

At a given instant in time, a 6 kg. rock is observed to be falling with an acceleration of 5.0 m/s. What is the magnitude of the force of air resistance acting on the rock?

2007-02-01 16:41:54 · 4 answers · asked by damon h 1

For this problem neglect air resistance and remember that weight = mg. How much force acts on a 0.01 kg coin when it is halfway to its maximum height?

2007-02-01 16:29:44 · 3 answers · asked by Tone_Loc 2

I'm stuck on 2 HW problems. This is for my Calc III class.

1) A projectile from the origin is to be fired at a target 600 feet away. There is a hill 300 feet high midway between the gun site and this target. At what initial angle of inclination should the projectile be fired?

*My guess to approach this is: Will this be a 2-part problem? Solving for an angle from origin to 300 ft then from 300 ft to 600? I don't know how to start exactly.

2) A point moves on a circle whose center is at the origin. Use the dot product to show that the position & velocity vectors of the moving point are always perpendicular.

*I know the answer is scalar, and must be 0 for the vectors to be perpendicular. That's as far as I can get for now. I will keep trying things till tomorrow morning (the last time I can check here before turning in these in).

Any helpful suggestions for either problem or both will be greatly appreciated. Thank you for your time and help! :)

2007-02-01 16:25:46 · 1 answers · asked by PuzzledStudent 2

theres a bowl at the forest, but it wont fill any water when rianing.

2007-02-01 16:05:53 · 4 answers · asked by chajen v 2

2007-02-01 16:02:34 · 4 answers · asked by JAN 7

A copper block rests 30 cm from center of a turntable. Coefficient of static friction between surface and block is 0.53. Turntable starts from rest and rotates at a constant angular acceleration of 0.5 rad/s^2. At what time wil block start to slip? (hint: normal force= weight of block)

2007-02-01 15:59:54 · 2 answers · asked by Anonymous

I can't seem to come up with the right combination of equations to solve this problem. I know that V=IR and P=IV, but I'm not having any luck with the substitutions I'm making. Can anyone give me some guidance on how to approach a problem like this and find two different resistance values? Not looking for the answer, as I need to solve it myself, but I am in desperate need of guidance. Any help would be greatly appreciated!

A light bulb is wired in series with a 132 ohm resistor, and they are connected across a 138.0 V source. The power delivered to the light bulb is 22.7 W. What are the two possible resistances of the light bulb?

low value= ?
high value=?

2007-02-01 15:56:28 · 2 answers · asked by larkinfan11 3

like if you were in a cave at the top of a hill.

2007-02-01 15:44:01 · 5 answers · asked by johnec4 3

"Energy cannot be created or destroyed", and magnets continually exert force. Do they lose their power over time?

And a related question, do atoms gradually lose their energy? I mean, the electrons constantly orbit the nucleus, and that takes energy. What happens if they run out of energy?

2007-02-01 15:40:12 · 12 answers · asked by Coffee-Infused Insomniac 1

A weather ballon filled with hydrogen has a volume of 115 m^3 when on the ground. A bag attached to the ballon has a mass of 2.3 kg. What weight of instruments can it carry and still make it off the ground?

2007-02-01 15:37:08 · 2 answers · asked by NoturTypicalBI! 3

what is the unit of measurement needed to heat 1 kilogram of water?

2007-02-01 15:29:16 · 2 answers · asked by method 2

Gauss's Law

a flat circle of radius 18 cm is placed in a uniform electric field of magnitude 5.8 x 10^2 N/C. What is the electric flux through the circle when its face is (a) perpendicular to the field lines (b) at 45 degrees to the field lines, and (c) parallel to the field lines?

Please provide step-by-step work if possible. Thank you!

2007-02-01 15:09:34 · 1 answers · asked by Sparkles 3

Considering the effect of gravity does that mean you would stop in the middle?

2007-02-01 15:07:03 · 20 answers · asked by Anonymous

2007-02-01 14:49:06 · 3 answers · asked by Anonymous

Anybody think we already have it secretly?

2007-02-01 14:49:02 · 5 answers · asked by thepaladin38 5

2007-02-01 14:28:26 · 3 answers · asked by Anonymous

I know p=mv but still don't totally understand.

2007-02-01 14:11:51 · 4 answers · asked by Jazz_Fingers 1

1.)A 10-kg crate and a 100-kg crate are both sliding without friction down a plane inclined at 20 degrees with the horizontal. What is the acceleration of each crate?

2.)A box slides down a frictionless plane that makes an angle of 35 degrees with the horizontal. A horizontal force of half the box's weight process the box against the plane. what is the boxes acceleration?

2007-02-01 13:35:34 · 1 answers · asked by 94z6ex 1

An electron with speed v0 = 29.5 106 m/s is traveling parallel to an electric field (v0||E) of magnitude E = 11.9 103 N/C.
(a) How far will it travel before it stops?
in cm
(b) How much time will elapse before it returns to its starting point?
in nano sec

2007-02-01 13:21:02 · 3 answers · asked by webogirl 2

At time= 0 an automobile already traveling at 30km/hr. accelerates at 3m/s for 2 seconds. During there two seconds, how far does it go?

What is the formula to figure this out?

2007-02-01 13:13:25 · 5 answers · asked by angelgirl 2

The title says it all, What happens when an UNSTOPPABLE object collides with an UNMOVEABLE object?

2007-02-01 13:11:18 · 9 answers · asked by Krinen 2

An automobile starts from rest and accelerates at 3m?s for 4 seconds. How fast is it going after the acceleration?

What formula do i use to figure this out?
Any help is appreciated.Thanks..

2007-02-01 13:08:55 · 4 answers · asked by angelgirl 2

You drive a car 1500 ft to the east, then 2500 ft to the north. If the trip took 3.0 minutes, what was the direction and magnitude of your average velocity?

2007-02-01 13:04:21 · 3 answers · asked by 123haha 1

2007-02-01 13:04:14 · 4 answers · asked by naeemah s 1