Physics - December 2007

1) a 215N box is placed on an inclined plane that makes a 35.0 degree angle with the horizontal. find the component of the weight force parallel to the plane's surface

2)you push a 325 N trunk up a 20.0 degree inclined plane at a constant velocity by exerting a 211 N force parallel to the plane's surface.
- what is the component of the trunk's weight parallel to the plane
-what is the sum if all forces parallel to the plane's surface?
-what is the magnitude and direction of the friction force?
-what is the coefficient of friction?

2007-12-19 08:43:10 · 2 answers · asked by emily K 1

A 10-g bullet hits a 200-g block of wood and sticks inside. The block is on the frictionless horizontal surface and initially at rest. What fraction of the bullet's kinetic energy is converted into the internal energy?

if only they gave me velocities =[

2007-12-19 08:37:03 · 3 answers · asked by jabba 3

if a tree is touching an electrical wire and we touch that same tree we don't get electrocuted?? why doesn't the tree light up.

2007-12-19 08:21:08 · 7 answers · asked by Anonymous

Given an object in constant circular motion, at a radius of r with (angle) = (omega) (times) t, apply rectangular conversion of polar coordinates and differential calculus to derive the perimeter speed and the scalar acceleration of the object.

2007-12-19 08:09:51 · 1 answers · asked by sapphireleech@sbcglobal.net 2

2007-12-19 07:09:13 · 3 answers · asked by Elestus V 2

2007-12-19 06:56:26 · 2 answers · asked by Brian C 1

I'm 90,000 miles from a distant 'virtual' planet. Call it a point. Beginning from zero, I continue to accelerate. Passing through that point I record my speed. (the mass of the planet can be anything).

I do this again while increasing my distance from this point to 110,000 miles. I record my speed at exactly 100,000 miles. (10,000 miles short of the point).

Are they the same speeds? Can someone help me to set this problem up so I know what I'm doing in the future? I'm not a great algebra student. Yes, I tried astonomy/space.

2007-12-19 06:45:32 · 4 answers · asked by toolmaker 1

A row of six 1.0 N wooden blocks is being pushed across a tabletop at a constant speed by a toy tractor that exerts a force of 1.3 N on the row. What is the coefficient of kinetic friction between the wooden blocks and the tabletop?

2007-12-19 06:40:56 · 2 answers · asked by Anonymous

A stagehand starts sliding a large piece of stage scenery originally at rest by pulling it horizontally with a force of 176 N. What is the coefficient of static friction between the stage floor and the 490 N piece of scenery?

2007-12-19 06:40:14 · 1 answers · asked by Anonymous

2007-12-19 06:30:02 · 3 answers · asked by Anonymous

Use any priciples of physics to answer

2007-12-19 06:25:16 · 2 answers · asked by FIZZZ 1

A 2.0-kg ball has a velocity of 15m/s downward just before it strikes the ground and bounces up with a velocity of 12m/s upward.

What is the change in momentum of the ball?

2007-12-19 06:09:21 · 2 answers · asked by xxtruflipxx 1

A sealed container has a volume of 0.020m^3 and contains 20g of molecular nitrogen (N2) which has a molecular mass of 28 u. The gas is at a temperature of 252 degrees celsius.

a) What is the pressure of the nitrogen gas?

b) If 500 Joules of heat are added to the gas, what is the change in its temperature?

2007-12-19 05:58:40 · 1 answers · asked by flipnv86@sbcglobal.net 1

A 2000-kg car rolls 80m down a frictionless 20 degree incline. If there is a horizontal spring at the end of the incline, what spring constant is required to stop the car in a distance of 1.0m?

2007-12-19 05:53:10 · 2 answers · asked by flipnv86@sbcglobal.net 1

A football is kicked with a speed of 18 m/s at an angle of 65 degrees to the horizontal.

a) How far does the football travel horizontally before it hits the ground?

b) What are the respective horizontal and vertical components of the initial velocity of the football?

2007-12-19 05:49:00 · 2 answers · asked by flipnv86@sbcglobal.net 1

Radioactive disintegration of some kernel occurs under the scheme:
X ----> 2 α 4 + 84 Po 218
Find the activity of element X in 11,4 day after the beginning of disintegration.
(use sub and superscript beside of α and Po)

2007-12-19 05:20:06 · 2 answers · asked by nilavan2004 1

please include ideas about particles in your answers

2007-12-19 04:54:07 · 6 answers · asked by roar 3

about 186,000 mile per second. That means that in one minute,light travels 11,160,000 miles.The star nearest Earth is the sun.Its about 93,000,000 miles from earth.Therefore,it takes sunlight about eight minutes to travel to Earth.so when you see the sun,you aren't seeing it as it was eight minutes ago.Since the stars are much farther away than our sun,imagine how far back in time youre seeing them.It's obvious that humans will never travel to planets around even the nearest stars.
Which statement is most likely to be opinion father than fact?
a.the fastest speed possible for anything is the speed of light.
b.Humans will never travel to planets around even the nearest stars
c.The star nearest Earth is the Sun.
d.When you see the Sun,you aren't seeing it as it is.

2007-12-19 04:31:13 · 3 answers · asked by Anonymous

2007-12-19 04:07:24 · 3 answers · asked by Anonymous

2007-12-19 03:39:52 · 5 answers · asked by Anonymous

the centripetal force on the car is 6,000 newtons. What is the radius of the curve?
a. 160 m
b. 80 m
c. 32m
d.16 m

2007-12-19 03:07:21 · 5 answers · asked by Anonymous

a. the earth rotates around the sun
b. the sun is the center of the universe
c. the earth rotates around the moon
d. planets orbit in circular paths around the earth

2007-12-19 03:02:07 · 1 answers · asked by Anonymous

Heisenberg's Uncertainty Principle says that we cannot determine both the exact position and velocity of a particle at the same. However, can't the particle be brought to a stop and thus, the principle be violated? Or would it break out due to something like Pauli's exclusion principle? How does it work? What if a particle temperature is reduced to an absolute zero? Won't it be totally out of energy??

2007-12-19 02:53:26 · 7 answers · asked by Anonymous

Unbroken glass appears to be unique. But when it is joined at broken ends, it appears to be made up of 2 piesces.Why it happens?

2007-12-19 01:43:15 · 2 answers · asked by shree_ruok 1

2007-12-19 01:37:03 · 6 answers · asked by Brian H 1

2007-12-19 00:26:10 · 13 answers · asked by Luis Lino F 1

I know that water is poor conductor. However, if you put your hand onto poor conductor, you should feel warm. But the fact isn't that, water is cold. What I want to ask is why water is cold?
Is that because water absorb the latent heat of vaporization from your hand? Or it is because they are fluid?

2007-12-18 23:17:02 · 3 answers · asked by Anonymous

2007-12-18 22:45:48 · 15 answers · asked by Anonymous

Einstien theory says that time is relative, but 1 s is 1 s, and i hour is 1 hour. Since no one can travel at speed of light, How can time be relative, is it ever proved or its hypothetical innovation of Einstien.

2007-12-18 19:53:34 · 4 answers · asked by Anonymous

Visit:
wbabin.net/science/tombe14.pdf

You'll find this abstract (one of 27 by Tombe) . . .

"E=mc² and Maxwell’s Fifth Equation
(A Dielectric Solution to E=mc²)

4/21/2007
Abstract. One of Maxwell’s original equations was the equation for simple harmonic motion. It will be shown how this forgotten equation can be reconciled with the double helix theory of the magnetic field to show that the famous equation E=mc² is actually Newton’s equation for the speed of sound in a solid."

You might say he really got my attention!


In his brief abstract, Tombe works through very quickly here and soon comes to this point:

“If we write mass m as the product of the areal density ρ and the surface area of the rotating dielectric πh²,
the area terms will cancel out and we will be left with,
c² = K²/ρ (Newton’s Equation for the Speed of Sound)”

I'm only clever enough to understand formulas and their transitions, but haven't a clue whether or not it makes sense, help please!

2007-12-18 19:20:14 · 2 answers · asked by rajjpuut 3