Physics - September 2007

In designing rotating space stations to provide for artificial-gravity environments, one of the constraints that must be considered is motion sickness. Studies have shown that the negative effects of motion sickness begin to appear when the rotational motion is faster than approximately 1.65 revolutions per minute. On the other hand, the magnitude of the centripetal acceleration at the astronauts' feet should equal the magnitude of the acceleration due to gravity on earth. Thus, to eliminate the difficulties with motion sickness, designers must choose the distance between the astronaut's feet and the axis about which the space station rotates to be greater than a certain minimum value. What is this minimum value?

2007-09-25 15:27:03 · 1 answers · asked by xteen 2

How can I make a self propelled car?
I am using a rubber band type source for power. I cannot apply any kind of force to the car. I also have to reach 60 meters.

Can anyone help me?
If this helps, I am using a structure similar to a 2 liter V8 bottle.

Sorry, but I'm not alllowed to use any sort of launching device.

2007-09-25 15:24:23 · 1 answers · asked by Luna 4

something to do with the doppler effect and supersonic speeds

2007-09-25 15:21:20 · 2 answers · asked by To-the-Stars 4

lets say there was a bullet shot completely parallel with the ground, and at that same moment the bullet it shot, an identical bullet is dropped from the same height as the shot bullet. My question is will both bullets reach the ground at the same time? Or will the fact that the bullet was shot affect the speed of its fall?

2007-09-25 15:11:51 · 6 answers · asked by master3rer 1

#1) An object with mass m1 = 5.00 kg, rests on a frictionless horizontal table and is connected to a cable that passes over a pulley and is then fastened to a hanging object with mass m2 = 12.0 kg. Find the acceleration of each object and the tension in the cable.
#2) Two packing crates of masses m1 = 10.0 kg and m2 = 3.50 kg are connected by a light string that passes over a frictionless pulley. The 3.50 kg crate lies on a smooth incline of angle 40.0°. Find the acceleration of the 3.50 kg crate.

2007-09-25 14:56:42 · 1 answers · asked by venney2004 2

Just always wondered about it, and wanting to find out if anyone has gotten he answer from personal experience.

2007-09-25 14:41:08 · 9 answers · asked by Dave K 2

i believe there is no end to the world of the small just like there is no end to the vastness of the universe.no matter how many times we cut something it becomes smaller.atom photon etc.something cannot become nothing no matter how many times you cut it..?

2007-09-25 14:33:34 · 5 answers · asked by mark w 1

2007-09-25 14:01:28 · 6 answers · asked by evans m 1

2007-09-25 13:48:13 · 3 answers · asked by Anonymous

A sphere conductor has a radius of 14cm and charge 26 * 10^-6 C. Calculate the electric field and the electric potential at:
1. r = 10cm
2. r = 20 cm
3. r = 14 cm from the center

2007-09-25 13:46:06 · 1 answers · asked by southsnow88 1

2007-09-25 13:42:01 · 8 answers · asked by Anonymous

www.nullphysics.com

"the Science of Uniform and Unconditional Reality"....

2007-09-25 13:34:57 · 1 answers · asked by meanolmaw 7

A dolphin jumps with an initial velocity of 11.5 m/s at an angle of 40.0° above the horizontal. The dolphin passes through the center of a hoop before returning to the water. If the dolphin is moving horizontally when it goes through the hoop, how high above the water is the center of the hoop?

2007-09-25 13:21:15 · 1 answers · asked by lstntht 1

I got this question wrong on my test but I don't understand why.
-----An object is thrown up in the air, it reaches its max altitude. What is its acceleration at max altitude?

I put 0, the correct answer is -9.81. What I don't understand is how an object that is not moving can have an acceleration. The object is at rest, therefore I don't understand how it can feel the effects of gravity at the highest altitude. Now if the object fell for even .000000000000000001 seconds I could see how gravity would cause it to freefall. But I don't see how acceleration can pertain to an object that has no velocity.

2007-09-25 12:50:01 · 2 answers · asked by mike L 2

I need help in solving a Physics puzzle question and help is highly appreciated.

The question is:

Imagine, for the purpose of this excercise that the earth is a smooth sphere. A rope is tied tightly around the earth at the equator. If the rope is then loosened so that 9 FEET of slack is now added uniformly around, which of the following creatures could possible crawl under the rope?

A) Amoeba
B) Ant
C) Mouse
D) Cat
E) Large Dog
F) Donkey
G) Giraffe

Thanks!

2007-09-25 12:48:36 · 2 answers · asked by UPS_b757Pilot 1

A pendulum is 0.8 m long and the bob has a mass of 1.0 kg. At the bottom of its swing, the bob's speed is 1.8 m/s. What is the tension in the string at the bottom of the swing?

2007-09-25 12:39:24 · 2 answers · asked by hehasnoidea2001 2

A box sits on a horizontal wooden board. The coefficient of static friction between the box and the board is 0.25. You grab one end of the board and lift it up, keeping the other end of the board on the ground. What is the angle between the board and the horizontal direction when the box begins to slide down the board?

2007-09-25 12:38:20 · 2 answers · asked by Anonymous

why is it that no matter what time or day, the past always seems better?

2007-09-25 12:35:26 · 3 answers · asked by Anonymous

Three point charges which initially are infinitely far apart are placed at the corners of an equilateral triangle with sides d. two of the pt charges are identical and have charge q. if zero net work is required to place the three charges at the corners of the triangle,

2007-09-25 12:23:25 · 1 answers · asked by Bryan s 1

I need help with this physics problem. I have been trying to solve this problem for 2 hours but I can't find the right answer.
Here's the problem:

A rocket moves upward, starting from rest with acceleration of + 29.4 m/s^2 for 3.98s. It runs out of fuel at the end of the 3.98 s but does not stop. How high does it rise above the ground?

In the back of the book the answer is 931 meters, but I want ot know how to get there.

Thank you for your help!!!!

2007-09-25 12:20:07 · 1 answers · asked by . 6

A soccer ball is kicked with a speed of 10.50 m/s at an angle of 20.0° above the horizontal. If the ball lands at the same level from which it was kicked, how long was it in the air? (Neglect air resistance.)

2007-09-25 12:13:16 · 1 answers · asked by pnknblackity 1

the relationship between them

HELP i need this for a lab due friday!

2007-09-25 11:54:53 · 7 answers · asked by s0ftballchic2oo9 2

starting from rest, a 5.00-kg block slides 2.50 m down a rough 30.0 degree incline. The cofficient of kinetic friction between block and incline in mk=0.436. what would the work done by the force of gravity be, the work done by the friction force between the block and incline be. and the work done by the normal force.

2007-09-25 11:42:57 · 1 answers · asked by markeesha h 1

Has mankind developed "time" as a measurement tool? Does time exist because "we" say it does? By rotation of the Earth time is calculated, because the Earth rotates does this establish time as absolute and only on Earth?

2007-09-25 11:32:58 · 3 answers · asked by edubya 5

Thrown 15.8m above the ground. With what speed does the water balloon hit the ground? How long does it take?

2007-09-25 11:28:01 · 1 answers · asked by Andy D 3

pull of the sun on the Earth. This is based on the knowledge that ocean tides are caused mostly by the gravitational influence of the moon.
Do you agree with these ideas? Please explain why you do or do not agree.

2007-09-25 11:27:04 · 2 answers · asked by Josh 1

Spiderman steps from the top of a tall building. He falls freely from rest to the ground a distance of . He falls a distance of 4.00 in the last interval of time of 1.10 of his fall.

2007-09-25 11:22:54 · 1 answers · asked by Natiphy2007 1

The answer is .62kJ. But how did they get it?

2007-09-25 11:21:25 · 1 answers · asked by Anonymous

is it true that when a firecracker espldes, mass is lost?

2007-09-25 11:16:02 · 2 answers · asked by Katie Ann 2

2007-09-25 11:12:52 · 1 answers · asked by m s 1