Physics - August 2007

I am confused...

2007-08-13 02:00:00 · 7 answers · asked by Anonymous

A truck and a car are both moving with a contant velocity of magnitude 'v'. Why is it difficult to change the motion of a truck when compared to the state of the motion in a car.

I'll give 10 points for the best answer.

It's easy. I'll give you a hint: The car has less mass

2007-08-13 01:46:45 · 5 answers · asked by that's me™ 1

A large truck and a car, both moving with a velocity of magnitude 'v', have a head-on collision and both of them come to a halt after that. If the collision lasts for one second:
1) Which vehicle experiences the greater force of impact?
2) Which vehicle experiences the greater change in momentum?
3) Which vehicle experiences the greater acceleration?
4) Why is the car likely to suffer more damage than the truck?

If you get it right, I'll give you 10 points! (it's so easy!)

2007-08-13 01:30:10 · 5 answers · asked by that's me™ 1

A girl jumps from a tree onto the ground. As she falls she speeds up.Explain in details how the law of conservation of momentum applies in this case?

Can I consider the girl and the earth(the ground) as a system?? Why or why not??
PLEASE HELP ME WITH MOMENTUM PROBLEMS. I would be so happy if you can tell me some advices about learning momentum. Thanks in advance!!!

2007-08-13 01:22:51 · 3 answers · asked by GooGi 1

A Swimmer is training in a river. The current flows at 1.45 m /s and the swimmer swims upstream a distance of 146 metres before swimming back to the starting point. If the total time for the swim is 189.0 seconds, what is the swimmers speed relative to the water? .... help.... quick.... :)

2007-08-13 01:01:58 · 3 answers · asked by rob s 1

Suppose that you are shopping in the mall around 7:00 p.m. on Christmas Eve. There are tons of last minute shoppers around when the fire alarm sounds. It turns out that there are only 3 doors to exit the ENTIRE mall from!

These three doors are set up in parallel. Or--
The three doors are set up in series.
Post which situation you would choose to exit through. Explain using at least 5 sentences, proper spelling and grammar, why you have chosen this situation and how it relates to Resistors in a circuit. Respond to at least one other classmate about their post.

2007-08-13 00:48:07 · 5 answers · asked by confused ~ 1

(a) A sample of liquid water of mass of 10 g and a temperature 20°C is placed into a large thermally insulated vessel containing steam at 100°C.

How much water will be present when equilibrium is achieved?

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(b) A glass flask whose volume is 1000.0 cm^3 at 0.0 ºC is completely filled with mercury at this temperature. When the flask and mercury are warmed to 55 ºC, 8.45 cm^3 of mercury overflow.

If the coefficient of volume expansion of mercury is
1.82 × 10^(-4) K^(-1) , compute the coefficient of volume expansion of the glass.

2007-08-13 00:28:30 · 2 answers · asked by Sarah W 1

tell me soon

2007-08-13 00:02:30 · 3 answers · asked by sweety 1

Really need to know the applications of specific heat capacity.

2007-08-12 22:40:05 · 1 answers · asked by pcyrilc 1

You have a big box which is large enough to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have.

How do you do it?

Note that you cannot send a key in an unlocked box, since it might be copied

2007-08-12 21:29:28 · 3 answers · asked by jarun_nager 1

A helium-filled balloon is tied to the floor of a car that makes a sharp right turn.
Does the balloon tilt while the turn is made? If so, which way?

2007-08-12 21:27:25 · 5 answers · asked by jarun_nager 1

2007-08-12 21:09:18 · 2 answers · asked by abi n 1

What is the scientific reson that kerosene contains more energy than fuelite or turps?

I've alredy done the experiment, but i don't know what the scientific reasoning is for these results.

PLEASE HELP!!!!!!!!!!

Cheers

2007-08-12 21:00:37 · 2 answers · asked by Dave 3

2007-08-12 20:49:44 · 15 answers · asked by nagar n 1

is it only because photon has a zero rest mass?

2007-08-12 20:43:10 · 8 answers · asked by mc 2

The rule says that light bends toward the normal line when it passes from less dense to denser media, but when I did the dipped pencil experiment, it always showed the opposite whatever angle I look from. Please help! I'm confused! Thanks!

2007-08-12 20:20:27 · 2 answers · asked by Milo 2

How does a transistor "amplify" current in a circuit?

2007-08-12 19:32:59 · 7 answers · asked by iqof300 3

2007-08-12 18:21:20 · 7 answers · asked by JAMES 4

The void of space that contains no familiar molecules... are there any recorded signs thus far of substance as the imperfect vacuum. To say, is the blackness without hydrogen present or any other familiar thing, deffinatly empty... or possibly filled with somthing very hard to detect with the familiarity of nature we are given on this planet? Have we not the intruments devised to map the structure of what seems as mysterious dark matter... or are there pieces that just haven't been put together to show evidence of the void unifying all things in the known and white unknown universe saying nothing in either isn't touching something from both being that all things are connected as far as is extending between dimensions?

2007-08-12 18:05:43 · 8 answers · asked by countrthght 1

Pretend the "O" is a ball what four forces would be attacking upon it? from both sides and vertically.


?
/\
?< O >?
\/
?

2007-08-12 18:00:49 · 3 answers · asked by questioneer112 1

2007-08-12 17:29:57 · 2 answers · asked by kalim 1

2007-08-12 17:21:09 · 5 answers · asked by kalim 1

A car travels 2.72 km in the x-direction, then
turns left 68 degrees to the original direction and
travels an additional distance of 3.2 km.
Calculate the x component of the car's net
displacement. Answer in units of km.

2007-08-12 16:15:49 · 4 answers · asked by Anonymous

Debunked again

We are told that light is both particle and wave.
Rubbish.
My theory is light is only a wave and not a particle.
It is as follows.
photons are nothing more than pieces of the same wave.
note I never say photons are particles only waves.
to create a wave of light all you do is shine a torch correct.
But what is happening here.
well we have a battery a light bulb , when we throw the switch electrons flow from negative to positive through the bulb filiment.
This energy is transformed into heat and radiation
The electromagnetic radiation light is only an oscillation of the fabric of the universe at a frequency we see, its a bit like holding a large coil spring between your hands, shake one side of the spring and a wave flows along the spring, however cut the spring and the wave stops. I believe that light requires the fabric of the universe to travel and that it does not produce its own wave in effect its only an Excitation of the fabric of the universe.

2007-08-12 15:30:15 · 14 answers · asked by Anonymous

2007-08-12 15:25:10 · 6 answers · asked by greek g 1

My dilemma relates to rocket man aging more slowly than his counterpart on Earth. What if our traveler is stationary, but the Earth moves away from him instead of him moving away from the Earth? (Ignore the effects of Earth leaving it's orbit, please) Is it the Earth folks that age more slowly, then? The relative motion between the traveler and the Earth is the same either way, and so why would it matter who's doing the moving?

If the answer is that it's not the relative velocity between the two that matters, but rather absolute velocity referenced to some theoretical motionless state, how could that state ever be determined? Also, if we imagined the whole universe was moving in some direction at high speed, and rocket man were traveling the opposite direction at the same speed, he would become motionless relative to this reference? So, instead of elongating in the direction of travel, he would shrink?!

Thanks for your help
Signed,
Relatively Confused

2007-08-12 15:17:54 · 7 answers · asked by philmeta11 3

Please check up also the question from Mik_K:
" What is the highest frequency of light, and why?"

I thought, a photon gets unstable at some frequency(-enrgy)-limit and decays into elementary particles like it happens in the immediate vicinity of a super massive nucleus (decay of vacuum, huge em-fielddensity). Is this right?
And, must a possible limitation on the energy of a photon be nessecerilly explained by plancks length? I guess, Einstein would give a quantummecanics-free explanation on this issue.

2007-08-12 15:05:01 · 4 answers · asked by Anonymous

My company, SunnIght Solar, wants to manufacture a solar powered water purifier - I have reviewed the UC and MIT web sites, however, the information on the problems with UV and PVC are not clear. markbent@sunnightsolar.com

2007-08-12 14:52:25 · 2 answers · asked by mark b 1

please and thank you very much!

:)

2007-08-12 14:26:09 · 6 answers · asked by Elizabeth 3

2007-08-12 13:26:16 · 1 answers · asked by Anonymous