Physics - February 2007

2007-02-02 15:41:58 · 5 answers · asked by Anonymous

A woman is reported to have fallen 137 ft from a building, landing on a metal ventilator box, which she crushed to a depth of 30 in. She suffered only minor injuries.

(a) Neglecting air resistance, calculate the speed of the woman just before she collided with the ventilator box.
in ft/s
(b) Calculate her average acceleration while in contact with the box.
in ft/s2
(c) Calculate the time it took to crush the box.
in seconds

2007-02-02 15:38:02 · 2 answers · asked by bonkti 3

It is TERRIFYING to me, that in the double slit experiment, electrons behave differently when we LOOK at them or when they are observed. They actually behave as waves even when 1 electron is fired at a time through the double slits. BUT, if you introduce a detector to see which slit the particle went through, it KNOWS it is being watched and decides to stop acting like a wave and it hits the screen and shows up as a particle. I think this is perhaps the most amazing thing ever discovered in science (at least one of them). What are the implications of this? Neils Bohr said "anyone who is not SHOCKED by quantum mechanics does not understand it." I am shocked, but what am I to think of this? What do you think?

2007-02-02 15:37:00 · 5 answers · asked by Anonymous

2007-02-02 15:10:37 · 4 answers · asked by Anonymous

2007-02-02 14:56:11 · 3 answers · asked by awantwin2004 2

We know that energy can be transformed from one form into another. But is there a boundary to this conversion? What I mean is, if one form of energy gets transformed into some other form, it gets converted fractionally; that is, is it true that the WHOLE of one form of energy does not get converted WHOLLY into another form & gets converted only fractionally? If yes, then what could be the reason for this?
Why I ask this is that our daily life situations suggest that this indeed happens. For example, when we hit a bell, our mechanical energy is converted into sound & heat energy (mostly), and NOT to ONLY ONE of them, although they are converted in varying proportions, as is evident. Several such examples could be found.

If this were indeed true, then is this conversion RATE arbitrary or is it quantized? Mathematical explanation with equations, please....

2007-02-02 14:50:42 · 6 answers · asked by Kristada 2

Lance Armstrong bikes at a constant speed up the Alpe d'Huez, a famous mountain pass. Assume his teammates do such a good job riding ahead of him that he can draft behind them and encounter no air resistance. This climb is described as "beyond classification" in terms of its difficulty. The climb is 13.8 km long at a 7.9% average grade (the grade, as a decimal, is the tangent of the angle of inclination). Assume that the combined mass of Lance and his bicycle is 83 kilograms. What is the magnitude of the work he does against the force of gravity?

2007-02-02 14:44:23 · 5 answers · asked by venom90011@sbcglobal.net 1

2007-02-02 14:42:39 · 3 answers · asked by mayling 1

2007-02-02 14:39:11 · 2 answers · asked by AlexTan 3

2007-02-02 14:38:03 · 7 answers · asked by AlexTan 3

Specifically, what components of an electrical system would be damaged or destroyed by an EMP? Transistors? Capacitors? Would an alternator work? How about a battery? A lightbulb? An LED? Transformers? Would copper wiring still be useable? A spark plug? I know a computer would be toast (barring a Faraday cage). But what would it take to make a car run again?

2007-02-02 13:57:32 · 5 answers · asked by Lokishadow 2

(a) How far from a 52.2 mm focal-length lens must an object be placed if its image is to be magnified 2.40 x and be real?
(b) What if the image is to be virtual and magnified 2.40 x ?

2007-02-02 13:23:35 · 3 answers · asked by Bob B 2

The circuit in the drawing contains five identical resistors. The V = 45 V battery delivers 44 W of power to the circuit.

http://www.webassign.net/CJ/p20-63.gif

I've been struggling with this one for several hours now and still cannot solve it. Can anyone give a concise and clear explanation of how to arrive at the correct answer? I'd really appreciate it.

2007-02-02 13:21:10 · 4 answers · asked by larkinfan11 3

You are pulling your sister on a sled to the top of a 15.0 m high, frictionless hill with a 10.0° incline. Your sister and the sled have a total mass of 50.0 kg. You pull the sled, starting from rest, with a constant force of 127 N at an angle of 45.0° to the hill. If you pull from the bottom to the top, what will the speed of the sled be when you reach the top?

2007-02-02 13:13:14 · 2 answers · asked by xiuhcoatl 1

I had a converstation with one of my customers today about how nano technology is going to change our future. What does this mean to you? I'm not very familar with it at this point in time.

2007-02-02 12:46:16 · 4 answers · asked by Lizzy 2

That is, that there are an infinite number of universes, many of which have copies of us doing different things (i.e. in one universe, I am a Christian...uggg! - while in ANOTHER universe, I am a Buddist priest, and in a third I am a Hare Khrisna, etc., etc...)

2007-02-02 12:44:55 · 8 answers · asked by Anonymous

I'm having trouble starting this problem.
Please help me.

2007-02-02 12:37:53 · 2 answers · asked by vicky p 1

Please help me with this question.
I'm having trouble starting it.

2007-02-02 12:29:29 · 2 answers · asked by vicky p 1

I have to do a balloon powered race car for my science class and I need some ideas of what materials I can use that would make it go fast, but stay on the ground.

Rules:
* The car must be powered by 1 balloon
* You can build the car out of anything
* It must have at least three wheels. Wheels are defined
as anything that is round and goes around.
* The wheels CAN NOT be wheels from a toy car. They
must be made out of something that was not originally
meant to be usedas wheels.
* The car may not leave the ground


Thank you so much for anyone that gives me ideas. I really appreciate it!

2007-02-02 12:10:35 · 4 answers · asked by miss pochacco 3

What is the "force carrier" of a magnetic field? Is it photons? I know that the field is generated by the aligned electrons in a permanent magnet, or by a moving charge, but what is the magic stuff flying through space around whatever is generating the field that actually makes up the B field?

2007-02-02 12:01:32 · 2 answers · asked by Veronica Almighty 2

When an electon absorbs a photon, is it able to hold on to it for a period of time, or does it emit the photon the instant it absorbs it? Kind of like a QED game of hot potato.
What is the experimental evidence?

2007-02-02 11:46:46 · 1 answers · asked by Veronica Almighty 2

thats a stupid question but its interesting

2007-02-02 11:08:23 · 3 answers · asked by Anthony D 2

If the Galaxy is always expanding then what are we expanding into?

2007-02-02 10:30:45 · 13 answers · asked by cleveralbanian. 2

If a radio show about the rainforest was broadcast in my house, could a nearby dog hear things at frequencies I'm not sensitive to? Could I use a basic tape recorder to run experiments on bats' ultra-sonic communication techniques?

2007-02-02 10:15:59 · 7 answers · asked by Loves Papillons 3

2007-02-02 10:07:57 · 3 answers · asked by scientist 1

Just curious.

2007-02-02 10:02:30 · 5 answers · asked by ChemGuy 2

2007-02-02 09:54:10 · 5 answers · asked by Anonymous

2007-02-02 09:47:24 · 24 answers · asked by Anonymous

Am having a problem with this and I'm not sure what I'm doing incorrectly. Please see below the problem statement for what I've tried so far. Any guidance would be appreciated!

A 62.0 ohm resistor is connected in parallel with a 121.0 ohm resistor. This parallel group is connected in series with a 17.0 ohm resistor. The total combination is connected across a 15.0 V battery.

(a) Find the current in the 121.0 resistor.
(b) Find the power dissipated in the 121.0 resistor.

When I combined the parallel resistors I came up with 41.5 ohms which I then added to the 17 ohms that this resistors was in series with to get 58.5 ohms. However, when I used the equation I=V/R (I= 15.0V/58.5 ohms) the answer I got was not correct for the current. I'm not sure what I'm doing wrong here.

2007-02-02 09:19:31 · 6 answers · asked by larkinfan11 3

in Farenheit ? ( roughly )

2007-02-02 08:58:26 · 5 answers · asked by Alexander C 1