Physics - November 2007

An 11.0 m, 230 N uniform ladder rests against a smooth wall. The coefficient of static friction between the ladder and the ground is 0.70, and the ladder makes a 50.0° angle with the ground. How far up the ladder can an 870 N person climb before the ladder begins to slip?
____m

2007-11-02 10:31:12 · 5 answers · asked by stars1234 2

After sitting at rest for a moment, the bee runs toward the other end with a velocity 1.49 cm/s relative to the still water. What is the speed of the 4.85 g stick relative to the water? (Assume the bee's motion is in the negative direction.)

2007-11-02 10:25:14 · 2 answers · asked by scoota 1

1. A fishing pole is 8 feet long. What effort force must Sylvia exert at a point 2 feet from the fulcrum end to lift a 2 pound fish?

2. Ian exerts a downward force of 30.0 N and moves that end of a lever down 0.50m, thus lifting the 0.10 m.

a) What is the mechanical advantage of this ideal machine?
b) How much does the load weigh?

2007-11-02 09:38:10 · 1 answers · asked by Anonymous

I was thinking that if we attach some sort of gears on the top of the pendulum line, it would be able to produce motion and ultimately we could draw energy from it. This would also be able to be done regardless of weather or sunlight.

Sound good to me, but why dont we do it, or hear about it?

2007-11-02 09:20:23 · 7 answers · asked by Anonymous

I want to learn QM. Do you have any advice or warnings? websites? books?

thanks.

2007-11-02 09:15:56 · 6 answers · asked by ? 3

Titanium (work function= 6.94*(10^-19) Joules) and Silicon (work function=7.77*(10^-19) Joules) surfaces are irradiated with UV radiation with a wavelength of 241 nanometers.

What is the wavelength of the electrons emitted by the Titanium surface?

2007-11-02 08:53:23 · 2 answers · asked by majoraganondorf 1

In Example 8-10, mass m1 = 2.40 kg is connected to mass m2 = 1.80 kg as shown. Suppose the two masses start from rest and are moving with a speed of 2.10 m/s just before m2 hits the floor.

http://i214.photobucket.com/albums/cc30/bkoz319/08-10ex.gif

(a) How much conservative work was done on this system?

(b) How much nonconservative work was done on this system?




Thanks sooooo much for your time!!!!

2007-11-02 08:48:46 · 5 answers · asked by SurferGirl9 1

would we be re-assembled with our soul ?

2007-11-02 08:47:54 · 12 answers · asked by Zipperhead 6

2007-11-02 08:20:48 · 3 answers · asked by Anonymous

2007-11-02 08:12:48 · 5 answers · asked by Anonymous

If the weight of a uniform boom is 2.00 kN, the tension in the horizontal guy wire supporting the boom a 5.60 kN weight is....?
Also given the length of the boom is 10 m and the height of the guy wire from the horizontal is 4 m.

Any help is appreciated - I have absolutely no idea what to do with this!

2007-11-02 07:43:51 · 1 answers · asked by emuhlee15 2

The diagram is a picture of a acute triangle and I have to find the angle of it, but it's a bit more complicated. There is a 3.7kg mass on the surface of the inclined plane and is connected to a 2kg mass and the pulley and string are massless and have no friction. The 2kg mass is acted upon by an upward force of 3.9N and has a downward acceleration of 4.6m/s^2. I found the tension in the connecting string and that 6.5N. What I don't get is how to find the angle and someone tried helping but what they did was 4.6=gsintheta but that was wrong.

2007-11-02 07:38:55 · 1 answers · asked by tanya 1

By means of a rope whose mass is negligible, two blocks are suspended over a pulley, as the drawing shows, with m1 = 10.3 kg and m2 = 43.4 kg. The pulley can be treated as a uniform, solid, cylindrical disk. The downward acceleration of the 43.4 kg block is observed to be exactly one-half the acceleration due to gravity. Noting that the tension in the rope is not the same on each side of the pulley, find the mass of the pulley.
______kg

http://www.webassign.net/CJ/p9-42alt.gif

2007-11-02 07:30:15 · 1 answers · asked by Anonymous

A rotating door is made from four rectangular glass panes, as shown in the drawing. The mass of each pane is 82 kg. A person pushes on the outer edge of one pane with a force of F = 76 N that is directed perpendicular to the pane. Determine the magnitude of the door's angular acceleration.
________rad/s^2

http://www.webassign.net/CJ/09_34.gif

2007-11-02 07:27:55 · 1 answers · asked by Anonymous

An object is shoot straight up to a height of H, when time is equal to T, given H and T find the time of the object at 3/4 the time it takes to get to H, or 3/4T. The result should be in fractions of H.

2007-11-02 07:09:31 · 1 answers · asked by Anonymous

A bullet of mass 0.010 kg and speed of 100 m/s is brought to rest in a wooden block after penetrating a distance of 0.10 m. The work done on the bullet by the block is

2007-11-02 06:47:41 · 1 answers · asked by maxk222 1

I tried asking this is Society and Cluture, but no one understood it i dont think... so here i am!

Its a little known fact that Nikola Tesla invented a machine which would draw power out of the naturally occuring electric feilds of the earth and be able to send it wirelessly through the ground at almost any distance and with the capacity to send huge amounts of power this way. (Google patent search "Apparatus for transmitting electrical energy" by Nikola Tesla 1914). the only reason it didnt happen is because Thomas Edison insisted on using the wire system so that they could sell power by usage. This philosophy has lasted until this day, and very few people are aware of the alternative possibilities.

how would history have been different if free electric power were implemented in the 1910's? How would the world change today if we built enough of them to power the whole world?

btw, this machine is NOT a fake, it was tested and confirmed. if you want more info on workings, ask

2007-11-02 06:42:43 · 2 answers · asked by nacsez 6

Im trying to work out the stress of a fishing line after connecting a fishing line to a pulleyboard and adding 100g weights one at a time onto the fishing line to create strain and stress.

I know the formula is Stress = Force divided by area

And i have already worked out the force acting on the fishing line for each 100 gram weights which are added. If i have done this right it is 0.1 (100 g) multiplied by 9.81 (gravity) to give 0.981.

Also i have the diameter of the fishing line as 35 microns (3.5 x 10 to the power of -5)

So the area of the cross section of the circular fishing line is needed and then needs to be multiplied by the length of the fishing line which is 1.2 metres.

Can anyone help me out with this please?

Thank you so much

2007-11-02 06:32:13 · 2 answers · asked by Anonymous

2007-11-02 06:12:33 · 2 answers · asked by mansa j 2

2007-11-02 05:39:21 · 5 answers · asked by Anonymous

Does wave actually exist or It is only a quality for physical phenomena?

2007-11-02 05:31:41 · 2 answers · asked by Freddie 2

horizontally 2.42m above the court surface. the net is 12m away and 0.90m high.
a.) what is the distance between the center of the ball and the top of the net?

2007-11-02 05:26:59 · 0 answers · asked by bigtregre 1

What are the effects of electromagnetic fields (EMF) on humans?

Please explain..thx

2007-11-02 05:18:30 · 2 answers · asked by bubba habba 1

where does it go

2007-11-02 05:09:00 · 48 answers · asked by lyvewyretnr 1

Newton's Third law states that : "Every action has a equal and a opposite reaction."

I have just modified it by adding one word stating : "Every action has a equal , opposite and a irreversible reaction."

"Irreversible" here just means that when there is any action which is considered as an example for newtons third law, the action cannot be reversed with respect to time.

Do you think this is valid? Do you cerebrate this statement?

2007-11-02 05:03:51 · 5 answers · asked by Prash B 3

i need this trivia until Sunday November 4. i need a trivia for each of this.

2007-11-02 04:22:47 · 5 answers · asked by Kate Rañola 1

2007-11-02 03:39:38 · 1 answers · asked by z A h J 1

If electricity is electrons pulled from the air I dont think it could work in a vacuum.

2007-11-02 03:19:49 · 8 answers · asked by Ken 1

I heard it's something to do w/ the sunrise and time???

2007-11-02 02:37:56 · 10 answers · asked by M.P. 5

Please explain how to calculate, I'm really lost

2007-11-02 02:22:42 · 2 answers · asked by Anonymous