Physics - December 2007

Hello

According to a college that works with me, he cliams that physics does not work in an uncontrolled environment.

He seems to be clear about the fact that he does not mean things are less accurate and subject to error due to unknown factors, and complexity of the real world.
He indicates that physics it's self is mostly not applicable to the real world.

I siad that a lot of physics is incorrect, but that physics still applies some how.
He seems to indicate that in the real world, it is large not based on any form of physics at all!

What the hell is he talking about?
What do you think of this and what philosophy is it?

Sabre

2007-12-10 08:23:27 · 5 answers · asked by Anonymous

A steel wire in a piano has a length of 0.8000 m and a mass of 5.000 10-3 kg. To what tension must this wire be stretched in order that the fundamental vibration correspond to middle C (fC = 261.6 Hz on the chromatic musical scale)?

2007-12-10 07:47:26 · 1 answers · asked by ricahrd l 1

A soccer ball kicked with a force of 13.5N accelerates at 6.5m/s^2 to the right. What is the mass of the ball?

2007-12-10 07:37:20 · 2 answers · asked by Anonymous

okay its in the title. and dont make it too college like. its only a 6th grade level answer i need. thanks!

2007-12-10 07:35:22 · 5 answers · asked by Kat 1

A 2.0kg otter starts from rest at the top of a muddy incline 85 cm long and slides down to the bottom in 0.50 s. What net force acts on the otter along the incline?

2007-12-10 07:18:03 · 4 answers · asked by Anonymous

The net force on the propeller of a 3.2 kg model airplane is 7.0 N forward. What is the acceleration of the airplane?

2007-12-10 07:14:12 · 2 answers · asked by Anonymous

A child causes a wagon to accelerate by pulling it with a horizontal force. Newton's third law says that the wagon exerts an equal and opposite force on the child. How can the wagon accelerate?

2007-12-10 07:08:38 · 2 answers · asked by x x italian baby x x 1

If the length of a piano wire (of given density) is increased by 5%, what approximate change in tension is necessary to keep its fundamental frequency unchanged?

A) Increase of 10%
B) Increase of 5%
C) Decrease of 5%
D) Decrease of 10%
E) Decrease of 20%

2007-12-10 07:07:09 · 1 answers · asked by ppapin 1

A golf ball is hit at a speed of 30 m/s at an angle of 450 above the horizontal. What is the maximum height of the ball?
(I get 22.96m, is this correct?)

2007-12-10 06:54:04 · 3 answers · asked by Anonymous

The forces acting on a sailboat are 390N north and 180N east. If the boat(including crew) has a mass of 270 kg, what are the magnitude and direction of the boat's acceleration?

2007-12-10 06:52:52 · 1 answers · asked by x x italian baby x x 1

2007-12-10 06:46:16 · 4 answers · asked by STORMY K 3

If a certain sample of monoatomic ideal gas has pressure of 100kPa. What is internal energy of 1m³ of gas.

Assume nothing except atoms of ideal gas do not interact and obey Newtonian mechanincs.

Please, people, do not use Maxwell distribution, and the like. The real solution is only three lines long and invololves no integration (at least expicitly).

2007-12-10 06:39:51 · 3 answers · asked by Alexander 6

A 1500-kg car is allowed to coast along a level track at a speed of 8.0 m/s. It collides and couples with a 2000-kg triuck, initially at rest and with brakes released. What is the speed of the two vehicles after they collide?
A) 4.4 m/s

B) 6.0 m/s

C) 4.6 m/s

D) 0.75 m/s

The answer I get is 3.4m/s because since the momentum is conserved the answer should be: (8m/s * 1500kg)/(1500kg+2000kg). Can someone confirm this?

2007-12-10 06:36:51 · 4 answers · asked by Anonymous

Why it so happens?

2007-12-10 06:23:00 · 5 answers · asked by Ghouri 1

A loaded flatbottom barge floats in fresh water. the bottom of the barge is 4.53 m below the water line. When the barge is empty the barge's bottom is only 1.08 m below the water line.
What is the difference between the pressure on the bottom of the loaded barge and the pressure at the water line?

I GOT THE FIRST PART.
the answer is 44394 Pa,
im not sure if its significant in answering the next part..


If the surface area of the bottom of the barge is 496 m^2, what is the weight of the load in the barge?

Answer in units of N.

like i said for the previous question, you dont have to give me the answer, a simple equation and explanation will be very helpful. THANKS!!

2007-12-10 06:20:48 · 3 answers · asked by (: 2

Any help would be greatly appreciated!
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.

2007-12-10 06:18:22 · 2 answers · asked by meeko 2

not in front of the Q?

2007-12-10 06:11:29 · 3 answers · asked by Anonymous

(a) Find the centripetal acceleration of the car. in (m/s^2)
(b) Find the force that maintains the centripetal acceleration (N)
(c) Find the minimum coefficient of static friction between the tires and the road that will allow the car to round the curve safely.

2007-12-10 06:05:01 · 1 answers · asked by Alyssa` L 1

If the resistance of an electric circuit is 12 ohms and the voltage in the circuit is 60 V, the current flowing through the circuit is

A. 720 A.
B. 0.2 A.

C. 5 A.

D. 60 A.

2007-12-10 06:04:00 · 5 answers · asked by Alfonso M 1

The magnitude of the voltage induced in a conductor moving through a stationary magnetic field depends on the _______ and the _______ of the conductor.

A. length, speed
B. color, capacitance

C. distance, circumference

D. resistance, current

2007-12-10 06:03:39 · 3 answers · asked by Alfonso M 1

The middle of the wire sags 0.25m at temperature 0C and 0.5m at 35C.
Linear density of the wire is 2kg/m.
Elastic koeeficient of the wire is k=600,000 N/m x m = 6e5N

What is coefficient of linear thermal expansion of the wire?

2007-12-10 06:02:14 · 1 answers · asked by Alexander 6

2007-12-10 05:14:17 · 5 answers · asked by jreim 1

2007-12-10 04:29:28 · 1 answers · asked by Anonymous

acting on the ball?

2007-12-10 04:06:41 · 7 answers · asked by Alexander 6

A charged particle Q is placed at distance R away from a semi-infinite charged wire with charge per unit length of σ.

The graph looks something like this:

---------------------->



Q

The charge is placed at distance R away from the wire, directly under the beginning of the wire


What is the total force acting on the particle?
Electrostatic forces are integrable, but can you derive the answer without actual integration?

2007-12-10 04:02:56 · 2 answers · asked by Alexander 6

What keeps my hand from not passin through a glass window, considering that both my hand and the window are both energy?

2007-12-10 03:45:32 · 9 answers · asked by Arnitak M 1

also is it the same for the thingy at the back of a freezer ???

2007-12-10 03:24:10 · 2 answers · asked by alainamorgan@hotmail.com m 3

2007-12-10 02:57:25 · 7 answers · asked by wanderer..... 2

2007-12-10 02:30:29 · 7 answers · asked by ashwin m 1

I understand a foot pound is the kenetic energy required to lift one pound one foot. A .30-06 has a rating of 2,829 foot-pounds of energy at the muzzle. I can't believe the .30-06 cartridge could lift a ton and a half one foot off the ground. So, what do these ratings really mean? How do the manufactures compute there findings?

2007-12-10 02:20:44 · 4 answers · asked by jack-copeland@sbcglobal.net 4