Physics - February 2007

My friends and I were out and sitting at a round glass table. One of my friends emphatically made a statement while pounding his mug on the table. It was kinda hard but not THAT hard....not hard enought where anyone would think the glass would break...yet the glass completely shattered. We noticed he hit the table exactly in the middle and the shatter pattern was circular all the way out. Just wondering if there is some physics explanation as to why the glass would shatter easier if you hit it exactly in the middle?

2007-02-17 08:34:36 · 5 answers · asked by Anonymous

2007-02-17 08:17:15 · 5 answers · asked by caldo47 1

2007-02-17 07:53:15 · 7 answers · asked by Anonymous

Don't tell me the answer!!! i want to figure it out on my own.
but i need someone to explain/walk me through the steps.
here is the problem:

A person skis down a hill, accelerating at a constant 2.00m/s/s. If it takes her 15.0s to reach the bottom, what is the legnth of the slope?

2007-02-17 07:50:41 · 3 answers · asked by LITTLE GREEN GOD 3

2007-02-17 07:19:44 · 1 answers · asked by brendon_tt 1

Give three differences between a sound wave and a radio wave.

2007-02-17 07:13:24 · 5 answers · asked by Anonymous

I have heard this claim many times in the past, but it seems awefully suspecious to me. What is the actual cause of this phenomenon?

2007-02-17 07:02:34 · 2 answers · asked by professional student 4

Plasma is "the fourth state of matter" but i want to go into more detail.

2007-02-17 06:55:34 · 8 answers · asked by Anonymous

just wondering

2007-02-17 06:43:24 · 6 answers · asked by macgyver 1

When I focus my eyes on a reflection in a mirror, I seem to focus differently than on the glass itself, for example on a smudge on the glass. This seems weird since the reflection is actually on the glass, not farther away as it appears to be.

When I look at a photograph, however, my eyes only focus on the paper itself, no matter what range of distance the photo appears to represent.

Why do my eyes act like the reflection in a mirror is farther away than the glass?

2007-02-17 06:35:06 · 6 answers · asked by Anonymous

I'm researching hyper-luminary space travel, black holes, gravitational collapse, imploding light, E=mc2, etc., and I don't quite understand most of it, as all refers to the Special Theory of Relativity (E=mc2) which I don't fully comprehend -- mostly because When i look it up in dictionary or encyclopedia (on-line or otherwise) it uses os many mis-understood physics terms and descriptions that I cannott grasp the simplicity of it -- I get confused and need a simple explanation so I grasp it conceptually in my mind.

Can you help me to understand this?

2007-02-17 05:50:00 · 4 answers · asked by mike f 1

k=19620 nm
g= 9.81

2007-02-17 05:34:18 · 1 answers · asked by brendon_tt 1

A 2.00-kg package is released on a 53.1 degree incline, 4.00 m from a long spring with force constant 120 N/m that is attached at the bottom of the incline. The coefficients of friction between the package and the incline are mu_s=0.40 and mu_k=0.20. The mass of the spring is negligible.

(a) What is the speed of the package just before it reaches the spring?

(b) What is the maximum compression of the spring?

(c) The package rebounds back up the incline. How close does it get to its initial position?

2007-02-17 05:33:11 · 1 answers · asked by M 1

2007-02-17 05:22:20 · 18 answers · asked by Mole 1

2007-02-17 05:20:24 · 5 answers · asked by Anonymous

Look at the two equations:

Position [m] = A [m s-2] time^2 + b [m s-1] time + C [m]

y = y (sub 0) + v (sub 0) + 1/2 a t^2

What does the A stand for in the first equation??

a) initial velocity
b) current position
c) 1/2 acceleration
d) currect velocity
e) initial velocity

please help! thanks

2007-02-17 05:00:18 · 3 answers · asked by Anonymous

An ariplane is flying at 150 mi/h (its speed in still air) in a direction such that with wind of 60.0 mi/h blowing from east to west, the airplane travels in a straight line southward. (a) What must the plane's heading (direction) for it to fly directly south? (b) If the plane has to go 200 mi in the southward direction, how long does it take?

2007-02-17 04:56:47 · 1 answers · asked by cj440288 1

2007-02-17 04:41:08 · 2 answers · asked by mohammadreza s 1

physics circular motion

2007-02-17 04:20:06 · 8 answers · asked by suhas_boeing 1

2007-02-17 04:09:28 · 1 answers · asked by lj 1

What should be the spring constant k of a spring designed to bring a 1200 kg car to rest from a speed of 109 km/h so that the occupants undergo a maximum acceleration of 5.0 g?

Any help here would be great!

2007-02-17 04:03:15 · 3 answers · asked by Anonymous

2007-02-17 03:45:25 · 6 answers · asked by Anonymous

Two railroad cars, each of mass 6500 kg and traveling 85 km/h in opposite directions, collide head-on and come to rest. How much thermal energy is produced in this collision?

Of course, answer should be in J.

2007-02-17 03:41:01 · 4 answers · asked by Jessie L 2

How do you explain this:

My bestfriend was sitting inside a library. When she glanced up towards a mirrored wall, she saw me wearing white, everything white. She described me as being very beautiful and radiant light was around me. The mirror reflection behind me reflected another part of the library. But when she looked again, the image was gone and the mirror was reflecting chairs, as how it should be. The catch is, I was not there at that time. I was at our classroom. She went around to look for me or anyone that could have been the person she saw, although she was sure it was me. We asked our psychology teacher, she said it could be something like an apparition. I can't really explain it. That happened over three years ago already. Does anyone have an idea? I posted this in the psychology forum but you may have other ideas.

2007-02-17 02:56:03 · 3 answers · asked by yellow_hubble 3

2007-02-17 02:49:28 · 9 answers · asked by Robert O 2

ok, we all knoe ohm's law: V=IR..if r increases,provided I remains the same,V will ALSO increase....but that does happen!....V decreases...i think i am BADLY confused in electricity...plz plz plz help! i am getting confusions after confusions....oh plz someone clarify!

2007-02-17 02:01:59 · 21 answers · asked by catty 4

Does that mean the clock in my car would be fractionally slower then the clock at home ,if they both kept perfect time?

2007-02-17 01:52:04 · 9 answers · asked by Anonymous

2007-02-17 01:43:18 · 3 answers · asked by Anonymous

I was doing matter in my physics course and i was working on derviving a formula for potential energy of atoms when forced out of equilibrium, but from the initial form of 0= e [ K^16 - 2*K^6 ]
When derviving you get the form K^16 = 2*K^6
(when K is equilibrium seperation over displacement, but their both the same figures, i think )
But yeah, i can see how you get there but that doesn't make sense mathematically and surely isnt true, so how can the final form be true if that isn't?
( r = r' / 2^1/6 )

2007-02-17 01:41:54 · 2 answers · asked by Anonymous

2007-02-17 01:26:04 · 5 answers · asked by Starmu 1