Physics - February 2007

Is it just me or is time going faster?

Even my kids say it -- something I never said as a child!! Is possible that the earth going around slightly faster or is it just because I'm getting old :) ?

P.S. -- I guess I'm angry that the long weekend is over (lol!).

2007-02-19 09:12:41 · 6 answers · asked by Wondering 4

To demonstrate standing waves, 1 end of a string is attached to a tuning fork w/ frequency 120Hz. The other end of the string passes over a pulley & is connected to a suspended mass M. The value of M is such that the standing wave pattern has 4 "loops." The length of the string from the tuning fork to the point where the string touches the top of the pulley is 1.20m. The linear density of the string is 1.0x10-4 kg/m, and remains constant throughout the experiment.
(a) Determine the wavelength of the standing wave.
(b) Determine the speed of the transverse waves along the string.
(c) The speed of the waves along the string increases w/ increasing tension in the string. Indicate whether the value of M should be increased or decreased in order to double the # of loops in the standing wave pattern. Justify ur answer.
(d). If a point on the string at an antinode moves a total vertical distance of 4cm during 1 complete cycle, what is the amplitude of the standing wave?

2007-02-19 09:01:12 · 2 answers · asked by Anonymous

2007-02-19 08:52:41 · 3 answers · asked by KnowItAll 2

2007-02-19 08:48:59 · 4 answers · asked by Anonymous

i know its time. but how is time related to dimensions. can someone clerify this for me.

2007-02-19 08:45:59 · 5 answers · asked by KnowItAll 2

Please don't bother if you are unable or unwilling to show a calculation.

2007-02-19 08:45:22 · 2 answers · asked by pattycake9000 1

A musician blows into an open pipe & produces its fundamental frequency. The pipe is 0.70 meters long. (Use velocity of sound = 343 m/s)
(a) What is the fundamental frequency?
(b) If he wanted to play a higher note, what would be the next higher frequency that can be played on this pipe?
(c) How many wavelengths fit inside the tube in this case?
(d) If the musician were to replace his open pipe with a closed pipe, what is the one possible length for the pipe if he wants to produce the same (higher) frequency?

any help would be greatly appreciated!!! thank u soooooo much!!! :)

2007-02-19 08:39:24 · 2 answers · asked by Anonymous

2007-02-19 08:32:33 · 2 answers · asked by Anonymous

A mass slides down a frictionless ramp as shown and collides with another stationary mass that is attached to a spring. The two masses stick together and enter into Simple Harmonic Motion.
(a) What is the total momentum of the 2 masses just after they collide?
(b) How much energy is lost in the collision?
(c) If the spring constant of the spring is 200 N/m, what will be the amplitude of the oscillation?
(d) What is the maximum speed the masses attain & where will this occur?
(e) What is teh acceleration of the masses when the spring compression is maximum?

pleaaase help....i'm so confused.....there's a pic w/ it that shows that the both masses are 5 kg each...& the mass that is sliding down the ramp was 2.5m high b4 is started sliding... any help whatsoever wud be apreciated...thank u sOoOo much!!!

2007-02-19 08:16:50 · 1 answers · asked by Anonymous

2007-02-19 08:14:05 · 1 answers · asked by Anonymous

2007-02-19 08:10:34 · 3 answers · asked by Anonymous

can you answer the question and explain it?

thank you.

2007-02-19 08:09:55 · 6 answers · asked by happy_cat218 1

Please answer this question and explain it to me.

thanx

2007-02-19 08:08:31 · 4 answers · asked by happy_cat218 1

2007-02-19 08:05:39 · 3 answers · asked by pattycake9000 1

i wanna figure the question on my own, the help i need is that....when calculating total time of flight, do u use the velocity of the plane relative to air (eg 300km/h) or velocity of plane relative to groung (eg 250 kn/h)?????

2007-02-19 08:04:16 · 3 answers · asked by Anonymous

Two packing crates of masses m1 = 10.0 kg and m2 = 6.50 kg are connected by a light string that passes over a frictionless pulley as in Figure P4.26. The 6.50 kg crate lies on a smooth incline of angle 35.0°. Find the acceleration of the 6.50 kg crate.

2007-02-19 08:02:19 · 3 answers · asked by Anonymous

2007-02-19 07:57:11 · 2 answers · asked by BaBY aNGel..~* 2

2007-02-19 07:54:19 · 4 answers · asked by Anonymous

Everytime I have an answer to the end of all space and matter I only find myself asking what could be on the other side of this END.------------?

2007-02-19 07:52:27 · 1 answers · asked by puddog57 4

2007-02-19 07:49:02 · 1 answers · asked by Anonymous

When your car moves along the highway at constant velocity, the net force on it is zero. Why, then, do you have to keep running your engine?

2007-02-19 07:48:14 · 6 answers · asked by angelgirl 2

What energy (work) is needed to spin up and then maintain a 3.5" diameter flywheel weighing 680 grs turning at 120 rpm on a horizontal plane?

The flywheel is comprised of flywheel plate and a stationary sun gear, weighing 200 grs. Attached to the flywheel are 4 planetary gears engaging the sun gear each weighing 120 grs. (Should you need the following info, the sun gear is 2" in dia and the planetary gears are 1" in dia. - assume no friction.)

Many thanks

2007-02-19 07:44:01 · 1 answers · asked by Willy 1

My understanding of relativity is that the speed of light is invariant in all reference frames, so how is it that light can slow down while it is in a high index material and speed back up when it exits the material while I remain in the same reference frame?

2007-02-19 07:42:24 · 3 answers · asked by professional student 4

two pple are sitting on a balanced teeter totter. one of them weighs 45.2kg and is 1.30 m away from point of balance. other person is 2.15 away from the point of balance.

is it:
T = Fd + Fd ---- > T = (45.2 X9.8 )(1.3) + ( 9.8m ) (2.15)
i put acceleration for gravity positive... is tat right also?
thx in advance for help

2007-02-19 07:39:38 · 1 answers · asked by Anonymous

An atom has two inergy levels with a transition wavelength of 694.3 nm. Calculate the % of atoms in the upper level at T=300 K

2007-02-19 07:38:33 · 2 answers · asked by dopplerjeff5000 2

I need some help here. I have a science power-point project, and I know of nothing interesting to do it on. It can be over any form of science, but I want it to be soemthing interesting to me. Does anyone have any ideas?

Also, I had an idea the other day of continuousness. There are many thigns that seem to be constant such as time. But is not unreasonable to think that everything has an end or is not constant. Every speicies we know lives and dies. Why can this not apply to everything?

Think about it. Who says that things run on for a constant period? Take carbon dating for example. Researches rely on the fact that their data is on a constant basis, but who says there could not be a slump or a bump to ignite more information?

Reasonably, it is more likely that all we know has end. Time has end. People have an end. Earth has an end. Everything has an end

2007-02-19 07:37:44 · 1 answers · asked by Ecclesiastes 3

The specific heat of a material can be used to identify it. For example, a 100.0 g sample of a substance is heated to 100.0°C and placed into a calorimeter cup (having a negligible amount of heat absorption) containing 150.0 g of water at 25°C. The sample raises the temperature of the water to 32.1°C. With the information, identify the substance.

I used two formulas.
Cmetal = Qgained by the water / (mass of metal)(change in temp of metal) WHERE Qgained by the water = (mass of water)(change in temp of metal)(4180 J/kg · K).

I first converted all masses to terms of "kg" and "Kelvin" first.

Qgained by the water = (0.15 kg)(305.25 K - 298.15 K)(4180 J/kg · K)
= 4451.7 J
Cmetal = 4451.7 J / (0.10 kg)(305.25 K - 373.15 K)
= 655 J/kg · K ???

The problem is I got a big specific heat, 655 J/kg · K, but it is probably wrong. Where did I make the mistake? I couldn't identify the substance, what is it really supposed to be? Thank you for your help.

2007-02-19 07:28:24 · 2 answers · asked by Anonymous

2007-02-19 07:23:24 · 1 answers · asked by Ayana T 1

2007-02-19 07:10:26 · 6 answers · asked by Anonymous

can you imagine placing three balloons in a box ?
one filled with water, one filled with air, the other filled with hydrogen. what would happen ? and how would gravity know
which balloon contained what
and on the same subject if you made a life sized replica of yourself out of poly styrene and weighted it would it weight the same as you ?

2007-02-19 07:08:22 · 6 answers · asked by leslie b 1