Physics - September 2007

There was a question on a recent Exam in my history class about "When did man invent time?" Now I realize i could have answered with the answer he [my teacher] wanted but I really wanted to discuss this to him, so I simply wrote on the Exam "Time was not invented by man, it was created with the universe", and as I expected.. he marked it wrong, so I argued it with him after class. I explained to him that time wasn't created by man, and he argued back that all time is, is a measurement of our existence, and that what I'm thinking of is that existence was created with our universe. Then I explained to him that yes he was right.. Man did create a way to "MEASURE time" and that a "second" is no different from a "metre" when talking about "distances".. I got the question wrong, and am wondering who is right in this situation!

2007-09-02 22:01:40 · 2 answers · asked by werdnerd 2

here the choices..
A. Acceleration
B. Displacement
C.Velocity
d. Speed

2007-09-02 21:16:47 · 3 answers · asked by Jason B 1

What is an inverting summer circuit and how does it work?

2007-09-02 21:07:14 · 1 answers · asked by Anonymous

Every doubling of sound power,we add 3dB and for every doubling of sound pressure 6dB. In what condition or situation do we double the power and pressure?

2007-09-02 20:59:45 · 2 answers · asked by Silvery_purple 2

A space shuttle circles the earth 660 km above the surface in 1 hr 32 min 10 sec. If the average radius of the earth is 6370 km, find the speed of the shuttle in m/s and km/hr.

As I understand it, I need to find the circumference of the earth (C = 2(pi)r). Is the number 660 km redundant?

Thanks.

2007-09-02 20:57:37 · 7 answers · asked by labelapark 6

ok I said in a few previous articles that light is not the ultimate speed.
You will believe me yet..
About superstrings and light being nothing more than a wave not a particle but a wave.
And all that light is nothing more than vibrations in the superstrings..

http://arxiv.org/abs/0708.0681

2007-09-02 20:51:57 · 12 answers · asked by emc.squared 1

Is there any way in which a sound could echo infinitely given the right surroundings, for example in a cave system?

2007-09-02 20:34:33 · 6 answers · asked by ceilteach_kitten 2

I've really being trying to figure this one out, if anyone could help me, I'd very much appreciate it.

If a car travelling at a speed of V can break at an emergency stop at a distance X. Assuming all other conditions are similar if the travelling speed of the car doubles, the stopping speed will be 4x. (I worked that part out)
A driver travelling at 40 km/h in a school zone can break to emergency stop in 3 meters. What would be the breaking distance of the car were travelling at 60 km/h.

Thanks in Advance.

2007-09-02 20:25:41 · 5 answers · asked by fatla00 2

Explain the characteristics of an ideal op amp

2007-09-02 20:24:04 · 1 answers · asked by Anonymous

Explain the operation of an inverting amplifier. What is meant by the gain of the operational amplifier? What is the relationship between inverting amplifier gain and Rf and Rr

2007-09-02 20:17:40 · 1 answers · asked by Anonymous

Alternatively, what is the average acceleration experienced by the ball to stop it? I think the following formula might need to be rearranged to solve for a.

v^2= v0^2+2ax

v0 = starting velocity
v = ending velocity
a = acceleration
x = distance

I am really bad at rearranging formulas, I managed to get a for acceleration on the left side of the equation as the denominator of v^2, but then I don't know how to get rid of v^2 so a for acceleration is by itself and ready to be solved. Any help would be appreciated.

2007-09-02 19:53:34 · 3 answers · asked by pamphlet_one 2

Is it something to do with the size of the metal's lattice? Can any metal exist as a single or a few atoms metallically bonded? I know that Sodium is highly reactive but I cannot understand why Na2 does not exist unless it is ionically bonded to something else.

2007-09-02 18:58:51 · 2 answers · asked by Gideon 1

Ok. Theres two laws that say matter and energy can neither be created nor destroyed, right?

I've been thinking about a way to possibly break those laws...

When matter moves at the speed of light, it becomes pure energy.

If that is so, something could accelerate to the speed of light and become pure energy. Thus destroying the matter and creating energy.

Does that seem possible?
Could that, in theory, break those laws?

2007-09-02 18:26:20 · 7 answers · asked by Andreios 3

in the cabin of a jetliner that cruises at 600 km/h, a pillow drops from an overhead rack to your lap below. since the jetliner is moving fast, why doesn't the pillow slam into the rear of the compartment when it drops? what is the horizontal speed of the pillow relative to the ground? relative to you inside the jetlinder?

2007-09-02 18:02:56 · 5 answers · asked by book worm 1

an elephant and a mouse would both have the same weight - zero- in gravitation-free space. If they were moving toward you with the same speed, would they bump into you with the same effect? Explain.

2007-09-02 17:40:53 · 5 answers · asked by stop global warming!!! 1

when a ball is thrown straight upward in the absence of air resistance, by how does the speed decrease each second?

after it reaches the top and begins its return downward, by how much does it speed increase each second?

how much time is required in going up compared to coming down?

2007-09-02 17:36:30 · 6 answers · asked by stop global warming!!! 1

if a freely - falling rock were equipped with a speedometer, by how much would its speed reading increase with each second fall?

2007-09-02 17:27:46 · 5 answers · asked by stop global warming!!! 1

im taking a class on physics AP and i got this summer packet to do over summer vacation and i have to read it then answer some questions, at first it seems like math, then i get completely lost when they bring in a bunch of formulas

does any1 have any advice/help they can give me to clear it up or help me understand it?

2007-09-02 15:32:25 · 7 answers · asked by .: ZEIDO :. 3

A ball is thrown vertically downward from the top of a 38.5-m-tall building. The ball passes the top of a window that is 13.9 m above the ground 2.00 s after being thrown. What is the speed of the ball as it passes the top of the window?

2007-09-02 15:12:41 · 2 answers · asked by Saber 1

the rubber worn from tires mostly enter atmosphre as pollution. Estimate how much rubber (kg) is put into the air in US every year. An estimate for a tire tread's depth is 1 cm when new and the density of rubber is about 1200 kg/m^3

2007-09-02 14:35:24 · 1 answers · asked by Anonymous

Is it consistent with Newton's second law?

2007-09-02 14:32:52 · 6 answers · asked by kntagler 1

moving with constant velocity , that is 19 m from the point of impact when the key is released. What is the speed of the boat?

2007-09-02 14:28:46 · 3 answers · asked by Saber 1

is 125 meters/second due east relative to the ground, what is the velocity of the plane being refueled relative to the
A) ground, and
B) refueling aircraft.

Correct me if I'm wrong:
The plane must have the same velocity as the refueling aircraft relative to the ground (and to the refueling aircraft itself) to keep up with it and continue going in the same direction.

2007-09-02 14:18:49 · 2 answers · asked by Diff 1

A flat circle of radius 18 cm is placed in a uniform electric field of magnitude 5.1x10^2 N/C.

b) What is the electric flux through the circle when its face is at 40° to the field lines?

Equation:
=EA cos ()
E=5.1x10^2
A=pi x .18^2 = .102
angle=40 degrees
(5.1x10^2)(.102)(cos 40)
=39.84
Yet it is wrong. What am I doing wrong?

2007-09-02 14:15:17 · 2 answers · asked by Jessie L 2

A boy runs 30 m east , 40 m north, 50 m west. What is his net displacement? can you please explain how you did it?

2007-09-02 14:11:53 · 3 answers · asked by pinkduck000 2

2007-09-02 13:45:20 · 7 answers · asked by Duy 4

2007-09-02 13:20:32 · 5 answers · asked by dannywild1 2

What are the magnitude and direction of the electric field at a point midway between a -8.0 µC and a +5.0 µC charge 3.5 cm apart? Assume no other charges are nearby.
FIND MAGNITUDE:

Equation:
E=(k/r^2)(absolute value q1 + absolute value q2)(10^-6)
plug in numbers:
E=(9.0x10^9/.035^2)(8+5)(10^-6) = 95510204.08 N/C

2007-09-02 13:19:21 · 2 answers · asked by Jessie L 2

"Suppose your hair grows at the rate of 1/30 inch per day. Find the rate at which it grows in nanometers per second. Since the distance between atoms in a molecule is on the order of 0.1 nm, your answer suggests how rapidly atoms are assembled in this protein synthesis."

I'm getting the answer 7.32 E -5 nm/second, but the software I enter my answers into is telling me it's wrong. What is the answer?

2007-09-02 13:14:47 · 2 answers · asked by justme 4

2007-09-02 13:11:44 · 5 answers · asked by arigont 2