Physics - May 2007

just need some examples of how its a real world application and how its used.

2007-05-30 01:26:20 · 5 answers · asked by Sylvia 1

2007-05-29 21:04:24 · 4 answers · asked by ramya 3

what is Acceleration phase: (how do we use it and when)
what is Deceleration phase:(how do we use it and when)
thanx!

2007-05-29 20:37:15 · 5 answers · asked by mhd1995 1

2007-05-29 20:05:14 · 3 answers · asked by mhd1995 1

A loudspeaker is connected to a spring (spring constant k = 15.9 N/m) as shown in the figure below. The speaker moves back and forwards in simple harmonic motion with an amplitude of A = 0.77 m. The mass of the speaker is m = 100 g.


What is the maximum speed of the speaker?

The answer is 9.71 m/s , but I dont know how to get it, Thanks for your help :)

2007-05-29 19:55:55 · 2 answers · asked by Anonymous

Jack and Jill are standing on a crate at rest on the frictionless, horizontal surface of a frozen pond. Jack has a mass of 75.7 kg, Jill has a mass of 45.5 kg, and the crate has a mass of 15.7 kg. They remember that they must fetch a pail of water, so each jumps horizontally from the top of the crate. Just after each jumps, that person is moving away from the crate with a speed of 4.10 m/s relative to the crate.

What is the final speed of the crate if both Jack and Jill jump simultaneously and in the same direction? (Hint: Use an inertial coordinate system attached to the ground.)

What is the final speed of the crate if Jack jumps first and then a few seconds later Jill jumps in the same direction?

What is the final speed of the crate if Jill jumps first and then Jack, again in the same direction?

(all solutions are in m/s)

2007-05-29 19:51:27 · 4 answers · asked by Anonymous

Time slows down for fast moving object relative to an observer, isn't it that the observer is also moving as fast relative to the object? Then the time dilatation must cancel itself, right?

2007-05-29 19:40:25 · 6 answers · asked by Bonifacio 2

so if water can be broken up in to paritcals that can be providing enery then how does it manage to be put together in the same way with out useing engery because it might have been used to be put together by something like a photon or something to do with quantam psyhics but y does it take a why does make such a bang if it was put together with nothing but space itself

2007-05-29 19:37:08 · 2 answers · asked by dangelo m 1

Nicola Tesla, clearly a brilliant mind ahead of his time, made many extravagant claims about his inventions. Some of the things he described seem to be out of the reach of even current technology/science. If Westinghouse, or some other wealthy patron, had continued his funding, what could he have achieved? Obviously more than the AC power and 3-phase motor he's known for today, but what? Was his broadcast power scheme workable? Could he have really 'Cracked the planet like an egg' as he claimed he could?

2007-05-29 19:36:51 · 5 answers · asked by AmigaJoe 3

I don't get these four. Please help!

1. A 120-volt power supply lights a lamp with a resistance of 600 ohms. What current flows through the circuit?

a. 0.2 A
b. 1.0 A
c. 5 A
d. 20 A

2. How many volts are required to produce a current of 20 amperes through a resistance of 100 ohms?

a. 5 V
b. 80 V
c. 120 V
d. 2,000 V

3. A fuse is designed to burn out when the current exceeds 10 amperes. If the voltage supply is 120 volts, what is the smallest resistance that can be used without burning out the fuse?

a. 6 ohms
b. 12 ohms
c. 110 ohms
d. 1,200 ohms

4. A 100-watt light bulb is used 100 hours in a given month. How much energy does it use in that month?

a. 10 kW x h
b. 100 kW x h
c. 1,000 kW x h
d. 10,000 kW x h

Thanks

2007-05-29 19:22:11 · 4 answers · asked by Anonymous

2007-05-29 19:18:47 · 2 answers · asked by gosaka 1

If yes, how do you know?
If no, does it mean forces take time to propogate.?.... explain

2007-05-29 19:10:02 · 6 answers · asked by wanderer..... 2

2007-05-29 19:01:07 · 4 answers · asked by Gnanam , 1

the force of gravity between 2 objects is 8 N. one object has a mass of 2 kg and other object is 100meters from it. what is the mass of the second object
F=G(m1xm2)/d2 G=6.67 x 10 -11 Nm2/ kg2

2007-05-29 18:54:20 · 2 answers · asked by Choiman 2

Just curious, can someone help me with this?

1. Which appliance probably uses the most energy in a given period of time?

a. a reading light
b. a solid state TV
c. a toaster
d. a clock

2. Which of the following conserves or saves the most energy?

a. Taking a 5-minute shower
b. Taking a 5-minute bath

3. Which of the following conserves or saves the most energy?

a. Cooking on a burner
b. Cooking in an oven

4. Which of the following conserves or saves the most energy?

a. Using an upright freezer
b. Using a chest-type freezer

5. Which of the following conserves or saves the most energy?

a. Keeping a freezer half empty
b. Keeping a freezer full

Thank ya!

2007-05-29 18:51:57 · 5 answers · asked by Anonymous

How is it possible for such a heavy thing to remain in the clouds?

2007-05-29 18:32:54 · 9 answers · asked by beekay 2

anyone who's good in science pls help me...

2007-05-29 18:23:42 · 7 answers · asked by mysterious girl this year!! 1

I have answers but don’t know how to get them. Thanks!
1) The hill is 8 m tall. How much work is needed to move a 150-kg sofa to the hilltop? (Answer: 1 * 10^4 Joules)
2) 300 N force is used to push a 145-kg mass 30 m horizontally in 3 seconds. Find work done on the mass (answer:9.00 kJ) & the power developed (Ans: 3.00 kW)
3) Al & his bike have a combined mass of 45 kg. Al rides his bike 1.8 km in 10 min at constant velocity. What’s Al’s kinetic energy? (Ans: 203 Joules)
4) A train has mass of 2.50 * 10^4kg. Its powered across a level track by an engine that made a thrust of 5 * 10^5 N for 509 meters. Find…
a. work done on the train (ans: 2.55 * 10^8 J)
b. change in Kinetic Energy (same as a)
c. final KE of train if it started from rest (same as b)
d. final speed of train if there was no friction: (ans: 143 m/s)
5) Al’s mass =28 kg. He climbs the 4.8 m slide ladder & reaches velocity of 3.2 m/s at bottom of the slide. How much work did friction do on Al? (Ans: -1.2 * 10^³ J

2007-05-29 18:21:32 · 2 answers · asked by susie q 2

the resultant intensity at the point as a result of interference would be?

2007-05-29 17:39:08 · 1 answers · asked by Anonymous

I know the Earth's escape velocity and I can calculate the acceleration due to gravity at any height above the Earth. Now, I would like to graph the position, velocity, and acceleration of a launched object over time.

I could use standard equations to find the height of the object after a certain amount of time, but my problem is different, because the acceleration due to gravity decreases as the height increases.

I would really like to know if there is a way to take into account the change in gravity when making a position-time graph, no matter what the initial velocity is.

2007-05-29 16:31:53 · 2 answers · asked by Pete 2

If something travels faster than the speed of sound in air it causes a sonic-boom resulting from the shock waves that are created at such speeds.

Sound travels faster in water than in air.

I am guessing if it happens in water it will cause tsunamis.

What do you all think would happen?

2007-05-29 14:57:34 · 6 answers · asked by WEAJR. 2

2007-05-29 14:19:56 · 7 answers · asked by puma 1

1) A 12 ohm, a 15 ohm, and an unknown resistance are connected in parallel. The total current of the combination is 12 A. The current across the 15 ohm branch is 4 A. What is the total voltage? What is the total resistance? What is the unknown resistance?


2)A 60 ohm, a 90 ohm and an unknown resistor are connected in series across a 130V battery. An ammeter in the circuit reads 0.67 A. What is the total resistance of the circuit? What is the size of the unknown resistor? What is the power dissipated in each resistor?

2007-05-29 14:11:30 · 2 answers · asked by Supreme_edge 2

Two balls, A and B, with masses m_a and m_b are connected by a taut, massless string, and are moving along a horizontal frictionless plane. The distance between the centers of the two balls is L. At a certain instant, the velocity of ball B has magnitude v and is directed perpendicular to the string and parallel to the horizontal plane, and the velocity of ball A is zero.

Find T, the tension in the string.

Express T in terms of m_a, m_b, v, and L.

2007-05-29 13:38:45 · 1 answers · asked by Anonymous

Hi guys,
I dont know how to get the answers for this problem, the answers are given, but I dont understand how to get there...

http://img76.imageshack.us/img76/6924/rotationandtranslationxg1.jpg
I had to upload this problem as an image file becouse there is a diagram.

Thanks in advance!

2007-05-29 13:21:38 · 2 answers · asked by Anonymous

Im having problems doing this example question, the answeres are given under each question but I dont understand how to get there...

I had to upload this question as an image file because there is a diagram to this question.
http://img76.imageshack.us/img76/7307/staticsir4.jpg

Thanks in advance!

2007-05-29 13:10:25 · 1 answers · asked by Anonymous

I was given this example but I dont understand how to get the answers, the answers are given below each question.

Thanks in advance, any help is really appreciated!

Please follow the link to the question as I couldn't write it all in here so I uploaded it as an image file.
http://img76.imageshack.us/img76/773/shmth6.jpg

2007-05-29 12:55:56 · 2 answers · asked by Anonymous

please help!!!!!!!!!!! what happens to it and why
please

2007-05-29 12:34:29 · 9 answers · asked by Jen 1

I need to evaluate a definite integral from minus infinity to plus infinity. The integrand (as a function of the variable p) is the product of F(p) and exp(i*p*x), where (p) is the integration variable, (x) is a given Real constant, and (i) is the usual sqrt(-1). The function F(p) is equal to (p/sqrt(p*p + m*m)), where (m) is another given (Real) constant.

As p goes to (+/-) infinity, F(p) approaches to (+/-)1, and the integral diverges in the strict sense, but it may converge to something like the Dirac-delta function, because the same integral with F(p) replaced by 1 everywhere indeed converges to 2*pi*delta(x), the Dirac-delta function. In fact, this integral may converge to a continuous function because F(p) is odd in p relative to p=0.

Can you help me with this integral?

2007-05-29 12:01:21 · 1 answers · asked by sensible 2

Just watching a thing about natural hallucinogenic plants and there ability to transport people in to different realms/dimensions. It just seems to me that there descriptions and drawings or paintings of their experience are very detailed and if they were just making it up or crazy it wouldn't be so detailed.

just wondering if there is more to go on other than a man under the influecne of hullcinogens testimony .

2007-05-29 11:09:02 · 2 answers · asked by Tone Teezy 2