Physics - April 2007

Speed and net work of bead down a frictionless track?

A bead of mass m = 5.10 kg is released from point A and slides on the frictionless track shown in Figure P5.30. The height of A is ha = 5.90 m.

Figure P5.30: http://i165.photobucket.com/albums/u78/RLB31384/p5-30alt.gif

(a) Determine the bead's speed at points B and C. point B m/s
point C m/s
(b) Determine the net work done by the force of gravity in moving the bead from A to C.

2007-04-10 12:28:51 · 1 answers · asked by ? 1

In a race over a distance s, runner A starts from rest and accelerates at a_1 for the first distance x and then runs at constant speed. Runner B starts from rest and accelerates at a_2 for the first distance x and then runs at constant speed. Runner A begins running as soon as the race begins but B first takes a nap to rest up.

What is the longest nap that B can take and still not lose the race?

2007-04-10 12:12:26 · 1 answers · asked by Anonymous

a baseball player uses a pitching machine to help him improve his batting average. he places the 75.7 kg machine on a frozen pond. the machine fires a .197 kg baseball horizontally at a speed of 36.1 m/s. what is the magnitude of the recoil velocity of the machine ?

2007-04-10 12:06:32 · 1 answers · asked by Anonymous

When I read about the magnetic colliders they are building, they talk about "crashing" particles together, releasing matter and/or energy that quickly disappears. Why does it disappear?
Is it something like a fish out of water? Fish needs water to live... These particles need something else to exist. Take away what they need; do they dissolve or do they change into something else?

2007-04-10 12:04:20 · 4 answers · asked by Anonymous

First please read the following site:
http://www2.corepower.com:8080/~relfaq/neg_temperature.html

Support all answers with documented evidence please.

2007-04-10 11:54:50 · 5 answers · asked by Justin 4

2007-04-10 11:54:35 · 1 answers · asked by tennischick746 2

-what happens to the kinetic energy if the mass is quadrupled (velocity stays the same)?
-what happens to the kinetic energy if the velocity is decreased to 1/5 the original velocity?

2007-04-10 11:54:18 · 1 answers · asked by hilary 2

Please show how, thank you in advance :)

1) a 4g object, with a charge of 20 microC on it, accelerates from rest through a potential difference, and afterwards, is moving at 2m/s, What is the potential difference ?

2)find the potential difference necessary when 200 J of work are needed to push a 1microC charge into an electric field

3)what potential difference is needed to give a +3 charge ion a KE of 50 MEV?

4) a charged metal sphere of radious 8 cm has a potential of -500v. with what velocity must an electron be fired toward the sphere if it is to just barely reach the sphere, when started from a position 15cm from the center of the sphere

2007-04-10 11:53:52 · 2 answers · asked by biowolf89 3

2007-04-10 11:41:02 · 3 answers · asked by Thomas 2

If you were talking by radio to an alien who has never been to Earth and has never seen anything manmade, how could you explain to him which direction is left and which is right?
He can not see you and you can not see him.
Or would it be impossible to explain "left" and "right" in words?

2007-04-10 11:40:57 · 5 answers · asked by Jeffrey K 7

You are given two carts, A and B. They look identical, and you are told that they are made of the same material. You place A at rest on an air track and give B a constant velocity directed to the right so that it collides elastically with A. After the collision, both cars move to the right, the velocity of B being smaller than what it was before the collision. Is either of the carts hollow? If so, which cart?

2007-04-10 11:38:34 · 2 answers · asked by Thomas 2

Speed and net work of bead down a frictionless track?

A bead of mass m = 5.10 kg is released from point A and slides on the frictionless track shown in Figure P5.30. The height of A is ha = 5.90 m.

Figure P5.30: http://i165.photobucket.com/albums/u78/RLB31384/p5-30alt.gif

(a) Determine the bead's speed at points B and C. point B m/s
point C m/s
(b) Determine the net work done by the force of gravity in moving the bead from A to C.

2007-04-10 11:21:11 · 1 answers · asked by Ruphert J 1

i need to know;
The procedure to be followed:
How the wavelength of the light falling on the LDR is determined:
How a measure of the intensity can be determined from the LDR:
The range of precision of any instruments that would be used:
The factors that would need to be controlled to ensure that it is a valid test:
Any safety precautions you would take when carrying out the investigation:
Particular features of the design that would ensure the accuracy and reliability of your results.

2007-04-10 11:13:43 · 2 answers · asked by chohiro 1

2007-04-10 10:51:09 · 18 answers · asked by Anonymous

2007-04-10 10:49:54 · 3 answers · asked by alberto_cmrg 1

A steel wire is used to hang a plant from a ceiling in a building’s atrium. The wire is 25 meters long and the hanging plant has a weight of 150N. When the plant is attached to the wire, the wire increases its length by 5 cm. What is the cross sectional area of the wire? What is the radius of the wire?

2007-04-10 10:34:49 · 3 answers · asked by GSU 1

2007-04-10 10:10:54 · 3 answers · asked by facedown55 1

2007-04-10 09:56:01 · 4 answers · asked by Alexander 6

about 5.6 down to about 1.4 meters. New high definition TV signals are in the UHF (ultra high frequency) band, with wavelengths considerable less than 1 meter. Will this shorter wavelength increase or decrease reception in "shadow areas" (assuming no cable)?

2007-04-10 09:39:33 · 4 answers · asked by mothsandbutterflies 1

with a graphical representation,what is the relationship between the velocity ratio of a machine and the applied load.

2007-04-10 09:29:16 · 1 answers · asked by Ofagbe George G 1

2007-04-10 07:58:01 · 5 answers · asked by Anonymous

2007-04-10 07:34:14 · 4 answers · asked by wiselymb 1

2007-04-10 07:27:08 · 2 answers · asked by ladona c 1

Some holes in earth which enlarge and suck up some things even us and close without leaving a small trace or scar.These are similar to BLACK HOLES.Can any one give me some more info about this?

2007-04-10 07:20:16 · 3 answers · asked by Venky 1

Wouldn't I be upside down!? Like if i jumped down head first, i would end up upside down in China...But if i took a plane i wouldnt be upside down! So what would happen?

2007-04-10 07:13:29 · 6 answers · asked by Anonymous

2007-04-10 07:05:24 · 6 answers · asked by Anonymous

i am doing a sicence project and need to no how much a quart, pint, liter, and gallon of water weigh. the awnser needs to be in pounds

2007-04-10 06:50:17 · 16 answers · asked by the jman 2

2007-04-10 06:50:13 · 2 answers · asked by stumped on physics 2

2007-04-10 06:47:07 · 4 answers · asked by Zach 1

2007-04-10 06:39:03 · 2 answers · asked by jlsmt666 1