Physics - December 2007

obviously the its faster than the speed of sound but is it faster than the speed of light?

2007-12-20 11:52:34 · 7 answers · asked by ty ty 2

2007-12-20 11:51:44 · 5 answers · asked by Anonymous

ok so in this scenario.... wat forces are involved and where?

ok so a boy whirls a block from directly above his head and releases it right when his arm is perpendicular to the ground....

ultimaltly i want to calculate the final velocity of the block as it leaves the boy's hand... but i want to make sure that i take all forces into account before calculating....

thank you

if anyone cod actually giv an answer with juss variables for specific values, it will b great...

thank you very much!

2007-12-20 10:58:45 · 2 answers · asked by quizzical 1

i had 100 probs 2 do i did all but these 16

7. identify the decomposition of u into the sum of two orthogonal vectors. One of which is the projection of v onto u
u = {2,-1} v= {1,-5}

8. find zw
z= 8(cos pi/6 + i sin pi/6) w= 4(con pi/12 + i sin pi/12)

I think its 32(cos pi/4 + i sin pi/3)

9. find the direction angle of the vector
v= -3i -10j

10. identify the trigonometric form of the complex number
3 – 8i

11. find the number by which the components of the vector can be divided to find the unit vector in the same direction
u= -3i + 3j
12. a box being pulled by two ropes . one rope exerts 55lbs and force of 24 degrees the other rope exerts 95 lbs and a force of 23 degrees. Find the direction and magnitude of the resultant of two forces

13. find the value of the expression:
(cos30 degrees + i sin 30 degrees) / (cos 75 degrees + i sin 75 degrees)

2007-12-20 10:45:33 · 2 answers · asked by Anonymous

The condition of apparent weightlessness for the passengers can be created for a brief instant when a plane flies over the top of a vertical circle. At a speed of 250 m/s, what is the radius of the vertical circle that the pilot must use?

thank you

2007-12-20 10:43:52 · 1 answers · asked by Mr. Tambourine Man 3

Question 1: An m2 = 1.4 kg can of soup is thrown upward with a velocity of v2 = 5.2 m/s. It is immediately struck from the side by an m1= 0.5 kg rock traveling at v1= 8.2 m/s. The rock ricochets off at an angle of α = 65 degrees with a velocity of v3= 5.4 m/s. What is the angle of the can’s motion after the collision? Answer in units of degrees.

Question 2: With what speed does the can move immediately after the collision? Answer in units of m/s.

PLEASE HELP ME PEOPLE !!! THANK YOU

2007-12-20 10:41:52 · 1 answers · asked by Anonymous

Computer-controlled display screens provide drivers in the Indianapolis 500 with a variety of information about how their cars are performing. For instance, as a car goes through a turn, a speed of 205 mph and a centripetal acceleration of 3.7g (3.7 times the acceleration due to gravity) are displayed. Determine the radius of the turn (in meters).

2007-12-20 10:38:48 · 1 answers · asked by Mr. Tambourine Man 3

1)Calculate the force of gravity between a human adult (mass = 88 kg) and the planet Mars (mass = 6.4 *10^23 kg), when Mars is at its closest to Earth (distance = 8 *10^10 m).

2)Calculate the force of gravity on a 10 kg mass at Earth's surface. The mass of Earth is 6*10^24 kg, and its radius is 6.4 *10^6 m.

3)Calculate the force of gravity on a 19 kg mass if it were 6.4* 10^6 m above Earth's surface (that is, if it were 2 Earth radii from Earth's Center.) The mass of Earth is 6 *10^24 kg.

4)Calculate the force of gravity between a newborn baby of mass 4 kg and the obstetrician of mass 70 kg, who is 0.2 m from the baby.

2007-12-20 10:36:02 · 1 answers · asked by eaglesblueflag 1

The length of the force vector is proportional to what property of a force?

Why is force not a scalar qusntity?

What happens to an object in motion when it experiences a nonzero net external force?

Why does it require much less force to accelerate a low-mass object than it does to accelerate a high-mass object the same amount?

How do mass and weight vary with altitude?

Distinguish between mass and weight

How does the force of static friction on a crate you cannot budge compare to the force you exert on it?
Assume that the crate is on a flat surface.

2007-12-20 10:28:32 · 1 answers · asked by AshleyAfinow 1

need help please

2007-12-20 10:26:07 · 1 answers · asked by Anonymous

...the resistance due to the skin effect?

There are formulas to calculate both, but I don't know how the skin effect resistance works at low frequencies where the resistance due to the skin effect is less than the DC resistance. Do they add? Rdc + Rac? Is the AC resistance ever less than the DC resistance?

2007-12-20 10:15:16 · 1 answers · asked by flaxseedoilandbalm 2

An astronaut weighs 8.00 x 10^2 newtons on the surface of Earth. What is the weight of the astronaut 6.37 x 10^6 meters above the surface of Earth?

2007-12-20 09:53:46 · 2 answers · asked by timothy z 1

A 0.013-kg ball is shot from the plunger of a pinball machine. Because of a centripetal force of 0.02 N, the ball follows a circular arc whose radius is 0.47 m. What is the speed of the ball?

thank you

2007-12-20 09:49:13 · 2 answers · asked by Mr. Tambourine Man 3

2007-12-20 09:26:29 · 6 answers · asked by Future 5

Can anyone tell me about different bicycle frames and briefly describe how the specific frame design is arranged to take the load?
Cheers.

2007-12-20 09:03:40 · 2 answers · asked by Devoted 1

Assuming the Law of Universal Gravitation F(g) = (GMm/r^2)(-r), apply the acceleration of gravity at the Earth's surface, the radius of the Earth, and the radius of the moon's orbit to calculate the acceleration of the moon.

2007-12-20 08:45:34 · 2 answers · asked by sapphireleech@sbcglobal.net 2

Given the potential energy of gravity is PE = -GMm/r and kinetic energy of motion is KE = (1/2)mv^2, apply conservation of energy to determine the final symbolic speed of an object initially at rest falling from an initial radial distance of r(0) to a final radial distance of r(f).

2007-12-20 08:43:27 · 2 answers · asked by sapphireleech@sbcglobal.net 2

ok, so i had a test today and me and my friends are debating the answer. The question is: A peice of metal is resting on top of a floating peice of wood in a tub of water. If the metal is removed from the peice of wood, what happens to the water level of the tub?

It stays the same?
It goes down?
or You cant tell from the info given?

2007-12-20 08:26:24 · 4 answers · asked by Patricia M 1

For any process to happen, in Nature, a number of alternatives are available, but the process is complete and stable at the least energy state and that is the best and unique alternative. If a glass of water is poured on the road, nobody has to calculate in which direction it has to flow, how much to be absorbed by the surface, how much to evaporate, how long to flow and where to accumulate etc. If somebody calculates these factors with the available data, it will still be nearest approximation. But Nature makes no mistakes. It takes all possible factors, even those not known to man, into account. The result is unique that cannot happen by any other available alternative. Any comments?

2007-12-20 08:19:33 · 2 answers · asked by Gee Waman 6

Hey, I need some help with this question, so any information would be great!

A 5.25-kg piece of wood (specific gravity= 0.5) floats on water (density= 1000 kg/m^3). A mass of lead (density=11,300 kg/m^3) is hung from the bottom of the wood block. What minimum mass of lead will cause the lead/wood combination to sink?

I found the density of wood to be 500 kg/m^3.
I know that there are two buoyancies going up and two weights going down.
I also know that I should use this equation:
Buoyancy= (density)(Volume)(gravity). But the thing is, there's no information that would be able to give me a volume, so that's where I'm stuck.

So please help if you can because it'll be much appreciated! Thanks.

2007-12-20 08:09:34 · 4 answers · asked by Anon. 2

I have noticed on y/a that there are some individuals whose atoms appear to be packed more densely. In fact, if their density becomes much more, it might open up a black hole or something. So, please, my friends, keep your atoms in line, okay?

2007-12-20 08:08:32 · 11 answers · asked by Anonymous

2007-12-20 08:08:00 · 9 answers · asked by Anonymous

2007-12-20 07:53:06 · 6 answers · asked by Anonymous

By how much is the energy stored in an ideal spring increased when it is stretch is increased from 8 cm to 16cm?

2007-12-20 07:33:13 · 5 answers · asked by flipnv86@sbcglobal.net 1

I have the following equations of motion:

mx'' = 0
my'' = 0
mz'' = qE

How do I find the solutions to these for a particle which starts from the origin at t=0 with an initial velocity v=(v_x + v_y + v_z) ? (v is a vector, x,y,z components)

2007-12-20 07:07:09 · 1 answers · asked by Anonymous

Spaceship A is traveling at 0.3c, and spaceship B is traveling at 0.4 c. Spaceship A sends a signal of frequency 1000 Hz. What frequency does spaceship B detect?

I had this on my final yesterday. This is what I tried:

I solved for their relative speed to each other, finding it to be 0.8c (I think, I can't quite remember, and I don't have my calculator nearby). Then I think I just plug that number into the relativistic Doppler effect equation. Can someone let me know how to solve this problem, or if I am correct. Thanks!

2007-12-20 07:00:27 · 2 answers · asked by Anonymous

and wher to gat any information

2007-12-20 06:45:39 · 15 answers · asked by tracey f 1

2 hours spent playing a shoot-em-up game.

or

2 hours spent trolling the physics section of Yahoo Answer?

2007-12-20 06:40:20 · 4 answers · asked by Anonymous

2007-12-20 06:35:06 · 18 answers · asked by Ilias A 1

And then thaws out again?

There's a project starting in May 2008 in a lab in Switzerland where they are going to try and test this theory. Some say that it may create some kind of black hole or something to where it will be possible to destroy Earth and possibly the entire universe. But, since it's never happened, no one really know what it will do. Just dandy, if you ask me.

2007-12-20 05:36:57 · 12 answers · asked by Anonymous