Physics - March 2007

My demonstration has to be 12 minutes long

2007-03-19 12:36:36 · 2 answers · asked by cesi_14 1

A lawn mower has a flat, rod-shaped steel blade that rotates about its center. The mass of the blade is 0.82 kg and its length is 0.56 m.
(a) What is the rotational energy of the blade at its operating angular speed of 3500 rpm? (in kJ)
(b) If all of the rotational kinetic energy of the blade could be converted to gravitational potential energy, to what height would the blade rise? (in m )

I've tried a few approaches to this problem and I seem to be stuck. Any help is greatly appreciated--thanks

2007-03-19 12:34:01 · 1 answers · asked by eureka4sureka 1

2007-03-19 12:26:23 · 6 answers · asked by Snarles 1

I've looked into it a little can anyone shine some light on this mystery?

2007-03-19 11:54:49 · 4 answers · asked by joe b 1

2007-03-19 11:48:26 · 5 answers · asked by 'Sup 2

what happens when one side of the battery is connected to the other ?

2007-03-19 11:14:57 · 2 answers · asked by crazzy 1

2007-03-19 11:13:09 · 1 answers · asked by rushil m 1

2007-03-19 11:09:23 · 8 answers · asked by Ariadne on TAURUS 2

I understand that quartz is used in the manufacture of semiconductors. How is this mineral able to conduct electricity? I think it is both covalently and ionically bonded. I am new to this stuff and cannot see if it is solid how electricity is able to be conducted.

2007-03-19 11:06:07 · 3 answers · asked by Gideon 1

Because the 2p orbital has slightly more energy than the 2s orbital, I was wondering which one is considered the valence shell? Is it the 2p orbital because it is the highest on the energy spectrum, or is it both the 2p and the 2s orbitals because they both have the same principle quantum number?

2007-03-19 10:55:16 · 2 answers · asked by evileye05477 2

without gravity pulling on us, causing parts to sag and bones to ache, would our bodys still succumb to such ailments. Also, would we live longer?

2007-03-19 10:25:40 · 7 answers · asked by Anonymous

2007-03-19 10:09:50 · 10 answers · asked by Anonymous

The formula given:

FA=F1X1 + F2 + X2 + WsXcg + F3X3 - (F1+F2+Ws+F3)XB/
(XA - XB)

The data measured/given/calculated:
Ws=1.49352N(newtons)
F1=1.67776N
F2=1.666N
F3=1.8874N
X1= 10cm
X2=40cm
X3=90cm
XA=.448kg
XB=.342kg
Xcg=50cm
I basically have to substitute numbers here but when i try to resolve it the answer doesnt match with this:

FA'=4.39

The answer must be somewhere along this amount since this is the experimental answer. Im looking for the numeric answer(the very especific right answer)

Any ideas?Hints? Thanks

2007-03-19 09:52:11 · 2 answers · asked by CJ 1

Rapidly rotating guidance laser installed on board
of satellite projects a spot on the ground. The spot
moves with constant speed v = 600,000,000 m/s with
respect to the ground.

What is the speed of the spot observed by tracking
system installed on board of jet fighter flying with
speed s = 1000 m/s in the same direction
(i.e. chasing the spot)?

2007-03-19 09:38:24 · 3 answers · asked by Alexander 6

A yoyo is constructed with a clever clutch mechanism in its axle that allows it to rotate freely and "sleep" when its angular speed is greater than a certain critical value. When the yo-yo's angular speed falls below this value the clutch engages, causing the yo-yo to climb the string to the user's hand. If the moment of inertia of the yo-yo is 7.4×10-5 kg•m2 its mass is 0.11 kg, and the string is 0.98 m long, what is the smallest angular speed that will allow the yo-yo to return to the user's hand? (in rad/s)

I didn't really know how to approach this question. Using the moment of inertia and mass, I thought I could find the radius to be 0.02594 m...but I didn't know where to go from there or if that will actually help me. How can I find theta and/or the time to solve this problem? Thanks in advance for any and all help!

2007-03-19 09:35:47 · 2 answers · asked by eureka4sureka 1

can somebody help me with this problem? http://blog.360.yahoo.com/blog-CMc13Q8ycqhQA2zD4EelxBwCrdYkuhw-?cq=1
you need to go to this link because there is a picture involved.
can you post answer showing your work so I can understand better. thanks.

2007-03-19 09:32:25 · 2 answers · asked by azulita 3

2007-03-19 09:29:59 · 5 answers · asked by Anonymous

i got an answer but im not to sure if it is right. =]

2007-03-19 09:20:00 · 5 answers · asked by Amber D 1

Please get Back to Me ASAP.

2007-03-19 09:18:18 · 8 answers · asked by Amber D 1

2007-03-19 09:13:15 · 26 answers · asked by Khalil A 1

I have to do a write up for a lab we did in physics class. We were working with pulleys. How do I find the total work done, and percent error for work done? Also, how do I find the number of strings involved?

2007-03-19 08:55:23 · 2 answers · asked by Anonymous

why does a sodium chloride solution boil at a higher temp than that of water. they have equal volumes

2007-03-19 08:55:14 · 2 answers · asked by haylie j 1

2007-03-19 08:49:08 · 3 answers · asked by azn17 1

What does the X in X-Ray stand for??

2007-03-19 08:43:25 · 7 answers · asked by t_man132003 2

the question is "How does the horizontal distance travelled by a ball projected from a ramp vary with the height of the ramp?"

2007-03-19 08:41:24 · 4 answers · asked by Andy P 1

1. Which statement is incorrect when considering gases?

A. Gas molecules are in constant, random motion at room temperature.
B. The reason that a gas can be stored in a container is that the molecules no longer move when confined to a container.
C. A reason why molecules of a gas fill a container is that there is no attraction between the molecules of the gas.
D. The reason that gases are compressible is because the molecules of a gas are very far apart compared to the size of the molecules.

2. According to Boyle's Law, a decrease in the pressure of a gas occurs when the..

A. volume is increased.
B. volume is decreased.
C. temperature is increased.
D. number of moles of gas is increased.

3. Three gases are used to fill a container. The mixture contains 0.250 atm oxygen, 385 mm Hg nitrogen, and neon. If the total pressure of the mixture is 825 torr, what is the partial pressure in mm Hg of neon?

A. 250. mm Hg
B. 190. mm Hg
C. 575 mm Hg
D. 440

2007-03-19 08:25:39 · 3 answers · asked by rachel b 1

I am currently in College Physics 2 and Lab (PHY 2054) and am having a little trouble with a question on the lab that deals with the oscilloscope. This lab is titled "Introduction to the Oscilliscope." Following you will find the question that i need help on...

How does the number of wave cycles seen on a screen for a fixed input frequency vary with the sweep time/division control setting? Why?



Any help would be greatly appreciated.

2007-03-19 08:20:02 · 5 answers · asked by Logan 4

2007-03-19 08:14:47 · 5 answers · asked by plolol 2

Our tech ed teacher says that circles withing circles are parallel. Our math techer says that only lines can be parallel and that our tech teacher probably should use the term "concentric circles." Who is right?

2007-03-19 08:06:24 · 9 answers · asked by Paul W 1

2007-03-19 07:53:15 · 3 answers · asked by Lefty 3