Physics - March 2007

Hi, i'm doing a physics project and i need to know how to calculate velocity of a falling object.

The question reads: using conservation of energy, calculate the velocity of a 2kg mass will strike the ground if it is raised 4 meters and then dropped.

can you at least provide the correct equation for this calculation.

Even if you dont know the units in meters, can you please provide the correct equation for this calculation.

thanks

2007-03-17 22:30:04 · 4 answers · asked by christinexox 1

a) Prove that the time evolution of the density operator rho (in the Schrodinger picture) is given by – rho(t)=U(t,to) rho(to) hermitian conjugate of U(t,to).
b) Suppose we have a pure ensemble at t=0. Prove that it cannot evolve into a mixed ensemble as long as the time evolution is governed by the Schrodinger equation.

2007-03-17 21:48:08 · 1 answers · asked by Lindsay 1

Physics topic

2007-03-17 21:37:15 · 5 answers · asked by joyce b 1

I found this out when I was in 3rd grade, and never got a proper explanation from teachers as to the process.

2007-03-17 21:29:21 · 9 answers · asked by riot 2

2007-03-17 21:28:37 · 5 answers · asked by Anonymous

2007-03-17 21:27:26 · 12 answers · asked by Anonymous

Physics topic

2007-03-17 21:25:08 · 9 answers · asked by joyce b 1

is it an optic phenomenon? and if so, what optic principles does it use?
or is it just to do with magnetism

2007-03-17 21:19:53 · 3 answers · asked by Anonymous

-acheivements
-brief bibliography
-awards
-etc...

2007-03-17 21:09:30 · 3 answers · asked by vroom 1

i have two problems i cant get please help

A) A bullet is shot at a target 200 ft away. if the bullet is shot at a height of 5 feet, with an initial velocity of 150 ft/s, and at an angel of 10 with the horizontal, when will it reach the target and what will be the height where it hits?

B) a disk is thrown from a height of 5 meter at an initial velocity of 65 m/s at an angle of 10 with the ground. after .5 second, how far has the disk traveled horizontally and vertically?

please help ireally dont understand

2007-03-17 20:54:35 · 5 answers · asked by Becky 2

2007-03-17 20:28:21 · 4 answers · asked by Tony J 1

in olden days during titanic how do the ship communicated with other ship

2007-03-17 20:02:00 · 2 answers · asked by road t 1

2007-03-17 19:47:35 · 1 answers · asked by ldsgds 1

please show your steps to solving this problem...
and leave the answer in scientific notation.. :D

2007-03-17 19:32:24 · 2 answers · asked by Anonymous

the temperature of 2.0 kg of water is 100.0 degrees C, but the water is not boiling, because the external pressure acting on the water surface is 3.0 X 10^5 Pa. normally, the boiling point of water at 3.0 X 10^5 Pa is 134 degrees C. determine the amount of heat that must be added to the water to bring it to the point where it just begins to boil?

2007-03-17 19:27:35 · 2 answers · asked by tico 1

many hot water heating systems have a reservoir tank connected directly to the pipeline, so as to allow for expansion when the water becomes hot. the heating system of the house has 76 m of copper wire whose inside radius is 9.5 X 10^-3 m. when the water and the pipe are heated from 24 to 78 degrees C, what must be the minimum volume of the reservoir tank to hold the overflow of water?

2007-03-17 19:23:18 · 2 answers · asked by tico 1

Should gravity have an effect on the thermometer when hung the wrong way?

2007-03-17 19:22:00 · 3 answers · asked by Anonymous

the concorde is 62 m long when its temperature is 23 degrees C. in flight, the outer skin of this supersonic aircraft can reach 105 degrees C due to air friction. the coefficient of linear expansion of the skin is 2.0 X 10^-5 (C-degrees)^-1. find the amount by which the concorde expands?

2007-03-17 19:18:39 · 3 answers · asked by tico 1

2007-03-17 19:12:36 · 2 answers · asked by Anonymous

a small crack occures at the base of a 15.0 m high dam. the effective crack area through which water leaves is 1.30 X 10^-3m^2. ignoring viscous losses, what is the speed of water flowing throught the crack?

2007-03-17 19:09:03 · 2 answers · asked by tico 1

Hey, could any 1 opt to answer that what the fundamental logi underneath the working of a Gyro.

2007-03-17 18:43:31 · 6 answers · asked by AmJ 2

2007-03-17 18:32:31 · 2 answers · asked by Anonymous

2007-03-17 18:16:57 · 11 answers · asked by Cricmaster 2

then up a mountain.

a.) What is the speed of the cars at the bottom of the valley?
b.) If the passengers are to feel 8g's ( 8 times their usual weight) at the bottom of the valley, what must be the radius R of the arc of the circle that fits the bottom of the valley?
c.) The top of the next mountain is the arc of a circle of the same radius R. If the passengers are to feel 0g's at the top of the mountain, what must be its height h'?

2007-03-17 18:15:53 · 2 answers · asked by rachie_grl6 2

A string wrapped around the disk is pulled with a constant force of 20 N. If the disk starts from rest,

a.) what is its kinetic energy after 5 s?
b.) what is the total angle change in theta that the disk turns through 5 s.
c.) show that the work done by the torque, tau * change in theta, equals the kinetic energy.

2007-03-17 18:13:32 · 1 answers · asked by rachie_grl6 2

Inlet Temp=277.5K
Temp rise in combustor=445K
Compression ratio= 4:1
exhaust gas velocity= 143m/s
Gamma=1.4 Cp=1.005 and Cv=.718
I can find temps and pressures at all stages but need to know the net power produced and can't figure how to use the 143 m/s

2007-03-17 18:07:12 · 1 answers · asked by Anonymous

one of the--copernicus,kepler,galileo

2007-03-17 17:41:47 · 3 answers · asked by ? 1

A constant friction force of 10 N acts on a 60 kg skier for 20 s. What is the skier's change in velocity?

Answer should be m/s.

2007-03-17 17:28:18 · 1 answers · asked by Jessie L 2

I am a 13yrold and i would love to understand the Theory of Relativity if anyone can explain the basics. All the best =]

2007-03-17 17:22:08 · 4 answers · asked by Marie M 1

radius is .762 meters
speed is 122 revolutions per minute
find speed of stone lodged in tire

2007-03-17 16:55:27 · 5 answers · asked by Anonymous