Physics - June 2007

Where would the stick most likely break?

The rock is closer to the weight being lifted. would it break at the fulcrum or in the middle of the stick- the longer half.

2007-06-16 17:49:48 · 5 answers · asked by pspinale2000 1

I love physics puzzles. Einstein called this type of physics gedanken physics because it required a person to use his or her mind to work through the problem. What follows is one of my all-time favorites.

Can a battleship float in a bathtub? Of course, you have to imagine a very big bathtub or a very small battleship. In either case, there is just a bit of water all around and under the ship. Specifically, suppose the ship weighs 100 tons (a very small ship) and the water in the tub weighs 100 pounds. Will it float or touch bottom?

a) It will float if there is enough water to go all around it.

b) It will touch bottom because the ship's weight exceeds the water's weight.

What do you think?

2007-06-16 17:33:18 · 5 answers · asked by ? 6

I'm looking for manufacture and, if possible, purchasing information on the Naco nanomicrophone. Internet search has turned up little current information. What I have is as follows:

The Register


Researchers at NASA's Jet Propulsion Laboratory claims ... devised the most sensitive listening device ever. ... the tiny microphone could theoreticaly detect the sound of a single cell growing. ... nanomicrophone is based on stereocilla -- carbon nanotubes -- might be able to literally "hear" cancer cells growing. ... highly directional and sensitive. testing the device was between 1998 and 2001.

I have two names: 1. Andrew Cleland 2. Flavio Naco

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Getting this information is very, very important. If you have good Internet search skills, your help would be greatly appreciated.

Thanks in advance.

2007-06-16 17:17:41 · 1 answers · asked by Bob D1 7

determine the heat flow through a wall
area = 100m sq
250 mm thick
change in temperature (between inside and outside temperature) = 10 degrees C
inside surface convective heat transfer coefficient = 8.3
outside surface convective heat transfer coefficient = 36
thermal conductivity of wall = 0.115

ive been given a few equations and canm figure each of those out individually but i cant seem to put it all together to beable to solve this. if any one can lend a hand that would be great

2007-06-16 17:16:52 · 3 answers · asked by Anonymous

is it on the inside of the wood's glass & wat is its function? cheers. =D

2007-06-16 16:06:41 · 2 answers · asked by Anonymous

2007-06-16 15:47:05 · 7 answers · asked by batabek 1

A 48.0 kg ice skater spins about a vertical axis through her body with her arms horizontally outstretched, making 2.50 turns each second. The distance from one hand to the other is 1.5 m. Biometric measurements indicate that each hand typically makes up about 1.25 % of body weight.

A) What horizontal force must her wrist exert on her hand?

B) Express the force in part (a) as a multiple of the weight of her hand.

2007-06-16 14:19:38 · 1 answers · asked by garagelu 2

Athlete will sprint 100 m, starting from rest, then leap onto a 20 kg bobsled. The person and bobsled will then slide down a 50 m long ice-covered ramp, sloped at 20 degrees, and into a spring with a carefully calibrated spring constant of 2000 N/m. The athlete who compresses the spring the farthest wins the gold medal. Lisa, whose mass is 40 kg, has been training for this event. She can reach a max. speed of 12 m/s in the
100 m dash.
(a) How far will Lisa compress the spring?
(b) The Olympic Commitee has very exact specifications about slope and angle of ramp. Is this necessary? If the committee asks your opinion, what factors about the ramp will you tell them are important?

2007-06-16 14:17:02 · 1 answers · asked by Anonymous

1. A ball of mass 0.10 kg moving with speed of 2.0 m/s hits a wall and bounces back with the same speed in the opposite direction. What is the cahnge in the ball's kinetic energy?

2. A shooting star is a meterid that burns up when it reaches Earth's atmosphere. Many of these meteroids are quite small. Calculate the kinetic energy of a meteroid of mass 5.0 g moving at a speed of 48 km/s and compare it to the kinetic energy of a 1100-kg car moving at 29 m/s (65 mi/h).

3. A gymnast of mass 52 kg is jumping on a trampoline. She jumps so that her feet reach a maximum height of 2.5 m abovoe the trampoline and, when she lands, her feet stretch the trampoline down 75 cm. How far does the trampoline stretch when she stands on it at rest?
[Hint: Assume the trampoline obeys Hooke's law when it is streched].

ANSWERS BELOW - Please explain :)

2007-06-16 13:56:03 · 1 answers · asked by Mark 1

2007-06-16 13:24:51 · 4 answers · asked by archy 1

Clarification:

Density of Gold: 20 g/cm3
Density of Silver/Gold mix: 10g/cm3

How does one figure out if a crown is pure gold or a mix without melting the crown.

2007-06-16 13:14:33 · 5 answers · asked by archy 1

Please show steps if possible.

2007-06-16 12:34:46 · 2 answers · asked by archy 1

2007-06-16 11:55:27 · 10 answers · asked by Just Me 2

What is the significance of Maxwell's Equations? I know they have to do with electromagnetism but how would you use them and why? I've taken calc I and II and still have no idea what they mean or how they unite electricity and magnetism. I know this is a rather difficult question to answer, but I would greatly appreciate any information you can give.

2007-06-16 11:42:52 · 2 answers · asked by MathGuy 6

2007-06-16 11:11:36 · 6 answers · asked by Anonymous

'Ello there. I'll be beginning college in a couple of months, and am having trouble deciding between majoring in physics or engineering physics.
Which major is more practical?
I know that a physics-major would require an advanced degree in order to work as a physicist, while an engineering-major can work as an engineer fresh out of college. And I do suppose it has a lot to do with my interests and goals etc.
But some opinions would be helpful.

Thanks much!

2007-06-16 11:07:29 · 9 answers · asked by Bill 1

The Grandfather Paradox is a contradiciton in the theory of time travel. It proposes the hypothetical situation of a man who goes back in time and kills his grandfather before his grandfather would have met his grandmother. This means the man travelling back in time never would have existed, meaning he could never have lived to go back in time in the first place. Doesn't this suggest that time travel is impossible becasue any alteration of the past would lead to different circumstances in the future?

2007-06-16 10:53:24 · 4 answers · asked by Oliver 2

A theory is, light particles can act in reverse time. Two subatomic particles do seem to communicate with each other regardless of how far apart they get in space & time. Its a theory that rests on a sort of time travel called Quantum Retrocausality. A backward concept that time can go backwards. Lasers, prisms, splitters, & fiber-optic cables can be used to detect non-local signaling between entangled photons. Experimenting with those and the above light particles just might work. What do you think?

2007-06-16 10:02:52 · 9 answers · asked by ZORRO 3

What is the voltage across C2 immediately after switch S is closed as in the diagram below? (Note, V=10.8 V.) zero
1) Calculate the equivalent capacitance of the circuit shown in the diagram above; where C1 = 8.55 mF, C2 = 5.55 mF, C3 = 1.15 mF, and C4 = 1.20 mF.
2) How much charge is drawn from the battery? the figure : http://capa2.cc.huji.ac.il/res/fsu/capalibrary/56CapacitanceCapacitors/Graphics/prob18av3.gif
*******
Two capacitors C1 = 7.0 mF, C2 = 14.6 mF are charged individually to V1 = 13.1 V, V2 = 3.6 V. The two capacitors are then connected together in parallel with the positive plates together and the negative plates together.
Calculate the final potential difference across the plates of the capacitors once they are connected. answer :6.679 V
1) Calculate the amount of charge (absolute value) that flows from one capacitor to the other when the capacitors are connected together.
2) By how much is the total stored energy reduced when the two capacitors are connected?

2007-06-16 09:49:09 · 3 answers · asked by Anonymous

Which one of the following is an example of a difficulty caused by thermal expansion?

A. buckled railroad tracks on a hot day
B. sagging power lines on a cold day
C. milkshakes melting
D. paint chipping off the side of a house


really appreciate it!!

2007-06-16 09:29:01 · 5 answers · asked by sunny 1

a. the binding energy per nuleus is least for nuclie of intermeediate size
b. the binding energy per nuleus is greater for nuie of intermediate size
c. they result in the production of neutrons
d. they result in the prouction of plutonium

2007-06-16 08:25:43 · 3 answers · asked by C H78611 1

If the Sun could slow down (or cool) instantaneously, how large would the Sun be? The size of the Earth? Pluto? Smaller?

2007-06-16 08:04:39 · 2 answers · asked by the_Bo0geYmaN 2

An object is on a scale, and a force of 200 Newtons is being pushed on it from above. The scale reads 75.0 lbs. What is the mass of the box (in kg)?

Now, I know the force is 200 N, g = 9.8 m/s^2. I need the mass. F = m*g. How do I incorporate the weight into this equation?

2007-06-16 07:50:04 · 2 answers · asked by Anonymous

2007-06-16 07:17:16 · 1 answers · asked by alex 1

A rock is dropped from a rooftop. It takes 10 seconds to hit the ground. what was the height the rock was dropped from in meters(ignore air resistance).

2007-06-16 06:48:05 · 4 answers · asked by Danny 4

whats the biggest factor that makes a solid a solid and a gas a gas?..for instance...Beryllium which has 4 protons and 5 neutrons is a solid and Radon which has 86 protons & 136 neutrons is a gas...is it the tighter atomic lattice a solid has?...what part does electrons play in making different states

2007-06-16 06:08:18 · 3 answers · asked by Anonymous

torque, angular velocity rotational kinetic energy and linear kinetic energy?...plz..I have this physics report i have to write about those listed above in relation to this wheel i designed. if you know any info about those things about can yooh please tell me. it would be much appreciated. even if you just tell me what they are in relation to a wheel.

2007-06-16 06:05:42 · 2 answers · asked by blahblahah 1

2007-06-16 06:01:00 · 1 answers · asked by saumya k 1

This is not about religion . Is scientific evidence available to find out why people do this?

2007-06-16 05:56:43 · 9 answers · asked by james h 2

ok, so how do you calculate the Earth's magnetic field using a compass and a current loop?

What formula do you use?

2007-06-16 05:48:51 · 3 answers · asked by sunny 4