Physics - December 2007

2007-12-12 11:24:14 · 9 answers · asked by hot_rod2k 1

A 70.0-kg astronaut pushes to the left on a spacecraft with a force F in "gravity-free" space. The spacecraft has a total mass of 1.0  104 kg. During the push, the astronaut accelerates to the right with an acceleration of 0.36 m/s2

Which one of the following statements concerning this situation is true?
A) The spacecraft does not move, but the astronaut moves to the right with a constant speed.
B) The astronaut stops moving after he stops pushing on the spacecraft.
C) The force exerted on the astronaut is larger than the force exerted on the spacecraft.
D) The force exerted on the spacecraft is larger than the force exerted on the astronaut.
E) The velocity of the astronaut increases while he is pushing on the spacecraft.

2007-12-12 11:15:29 · 1 answers · asked by gay kid 1

A spaceship in space suddenly explodes into smaller fragments. Which of the following is true concerning the smaller fragments?

A. Kinetic Energy Increases
B. Kinetic Energy Decreases
C. Momentum Decreases
D. Momentum Increases
E. Momentum is conserved

2007-12-12 11:10:43 · 1 answers · asked by Gerlad S 1

A 0.23 kg puck is initially stationary on an ice surface with negligible friction. At time t = 0, a horizontal force begins to move the puck. The force is given by = (14.9 - 2.79t2) , with in newtons and t in seconds, and it acts until its magnitude is zero. (a) What is the magnitude of the impulse on the puck from the force between t = 0.534 s and t = 1.76 s? (b) What is the change in momentum of the puck between t = 0 and the instant at which F = 0?

2007-12-12 11:03:54 · 1 answers · asked by shade o 1

A 0.23 kg puck is initially stationary on an ice surface with negligible friction. At time t = 0, a horizontal force begins to move the puck. The force is given by = (14.9 - 2.79t2) , with in newtons and t in seconds, and it acts until its magnitude is zero. (a) What is the magnitude of the impulse on the puck from the force between t = 0.534 s and t = 1.76 s? (b) What is the change in momentum of the puck between t = 0 and the instant at which F = 0?

2007-12-12 11:01:12 · 1 answers · asked by shade o 1

A loaded Boeing 747 jumbo jet has a mass of 2.0 105 kg. What net force is required to give the plane an acceleration of 2.8 m/s2 down the runway for takeoffs?

2007-12-12 10:31:57 · 1 answers · asked by Anonymous

a) has mass and a definite shape
b)combines with other matter and has mass
c) has mass and occupies space
d) combines with other matter and space space

2007-12-12 10:10:52 · 2 answers · asked by Anonymous

2007-12-12 09:49:56 · 7 answers · asked by jasmine 1

i have this regent physic question that i did but can't seem to find the answer to check my answer if it is right or not. can somebody help me with the answer.

here is the link to the regents, i need the answer to check my work.
http://www.lewport.wnyric.org/mgagnon/pdf/NewtonsLawsPretest.pdf

thank you

2007-12-12 09:31:15 · 1 answers · asked by jamiednae 1

Is there something to do with the traction or friction with spinning tires ?

2007-12-12 09:08:08 · 1 answers · asked by Anonymous

At what minimum speed must a projectile be launched from Greenwood High to score a direct hit on Warren High. distance = 10.64 miles

2007-12-12 08:45:33 · 1 answers · asked by Riley W 1

When you have a hot beverage, tea for example, and you place an ice cube in it, you hear some cracking noises. Then, you begin to see the cracks in the ice cube. Why is that?

2007-12-12 08:45:06 · 4 answers · asked by Anonymous

Light with wavelength 442nm passes throught a double slit sustem that has a slit separation d=0.400mm. Determine how far away a screen must be placed so that dark fringes appear directly opposite of both sides.

Please just show the steps, I don't require a numbercal answer.

Thank you in advance.

2007-12-12 08:41:03 · 2 answers · asked by Anonymous

2007-12-12 08:39:28 · 5 answers · asked by DaYrØn™ 2

I have read it makes them "safe" -- I am assuming this just means it makes them so they wont burn your eye out if it shines right in your eye. Is there more to it than that?

2007-12-12 08:09:36 · 2 answers · asked by bdb4269 2

2007-12-12 07:07:02 · 2 answers · asked by kanabbasi 1

A painter is going to use a board for support during a painting job. The board has a weight of 175N and the painter has a weight of 815N. THe left end of the board is supported by a sawhorse and the right end by a lightweight rope attached to an overhead bracket. The overall length of the board is 3.60m. When the painter stands at a distance of 2.70m from the left end of the board, calculate the tension on the rope. Express the result in N.

2007-12-12 06:50:08 · 3 answers · asked by jukeb0xqirl 2

Consider a Diesel cycle that starts with air temperature 300 K. The air may be treated as an ideal gas. If the temperature at the very end of isobaric expansion is 950 K, and gas compression ratio is 21, what is the efficiency ( in %) of this cycle? Give your answer with one decimal point accuracy

2007-12-12 06:44:23 · 1 answers · asked by Anonymous

This is a combination of probability and thought experiment.
It involves Schroedinger's Cat.
On a box a label is found :DO NOT OPEN THE BOX MIGHT ANNIHILIATE THE FUTURE.
What are the chances of finding the future?

Additional questions:
Suppose if there are N such boxes then what are chances of finding the future?

Suppose that the box has a label : OPEN THE BOX AND YOU MIGHT FIND THE CAT DEAD.
Then what are the chances of finding the cat dead if there are N boxes.

Multiverse questions>
Suppose that there are infinitude of Universes then what are the chances that a Future in some Universe was lost due to this observation?

If the multiverses interact then what are the chances of reaching from X to Y ?(Given that every possibility gets realized in some universe)

The questions are interesting because we can ask questions on logical relevance of Multiverse theory.
The Multiverse theory explains using the inescapable logic :
Because everything was possible no wonder that this happened.

But do we see the diversity and uncertainity due to Multiverse interactions???
How few are the universes and there interactions that the 10 consecutive heads are so rare???
think and respond

2007-12-12 06:02:54 · 3 answers · asked by Marissa B 1

2007-12-12 05:25:17 · 3 answers · asked by bunker 1

can someone explain the theory of relativity in laymans terms please

2007-12-12 05:22:43 · 7 answers · asked by Glenn F 5

Is it possible that different people could see colours differently? Could you and I both look at the sky, both knowing it is "blue", but what you see is a colour that I would call red (for instance) and what I see is a colour that you would call green and yet we have both been taught that that colour we see is called blue. A matter of perception. If that's the case, it could also be the true for the rest of our senses.
Hope that wasn't too deep for most of you.

2007-12-12 04:52:04 · 29 answers · asked by Anonymous

2007-12-12 04:37:16 · 12 answers · asked by john c 5

2007-12-12 04:23:23 · 5 answers · asked by Narok 1

2007-12-12 04:04:28 · 5 answers · asked by Narok 1

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2007-12-12 03:57:54 · 5 answers · asked by Anonymous

2007-12-12 03:51:45 · 5 answers · asked by Anonymous

We have a rocket parked in low height orbit around the Earth, which lies in the ecliptic plane, and want to launch the rocket outside the solar system without further help from other planets.

What is the best time of the year to initiate the launch fuel-wise?

2007-12-12 03:43:14 · 5 answers · asked by Alexander 6

The mass of a planet is 1/100 that of Earth and its radius is 1/4 that of Earth. If a person weighs 600N on Earth, what would he weigh on this planet.

The ANSWER IS 96N, how to I get to this?

given constants:
Radius of Earth: 6.37E6 meters
Mass of earth: 5.98E24 meers
Universal gravitational constant: 6.67E-11 Nm^2/kg^2

2007-12-12 02:48:38 · 5 answers · asked by bazjhi 1

To see the Question click on the link ..

http://solar.njit.edu/~cdenker/physics111h_quiz09.pdf

My comments : is do i have to use theta ..?
Do i have to use m1 , m2 , and m3
what are the components of the oxygen
How the equation looks like

2007-12-12 02:43:39 · 3 answers · asked by Anonymous