Physics - February 2007

2007-02-25 18:10:18 · 3 answers · asked by brokolay 3

im not too sure what happens and it also asks for explanation.can anyone help me with an explanation please.

2007-02-25 17:59:43 · 4 answers · asked by chris 1

2007-02-25 17:38:04 · 3 answers · asked by big_ray 1

Since white surfaces reflect all the light that strike them, as do mirrors, why is it that mirrors have reflections and not whiteboards?
My guess is that white surfaces scatter light, while mirrors do not. Is this correct? Any sources?

2007-02-25 17:26:31 · 4 answers · asked by Matthew P 4

I know that when light is sent out of a moving object, its speed still remains the same as if it was sent out of a stationary object. Keep in mind that there is red-shift and blue-shift in light waves though. Now, my question is: Do other waves follow the same principle as light waves? If I hit a metal pole with a hammer, would the sound waves traveling through it move faster if the pole was on a moving object versus the pole just sitting still in a stationary position? Or would the speed of sound remain the same, and instead the doppler effect would occur. Also note to yourself that the speed of light changes through mediums (it slows), and the speed of sound can change through mediums as well.

I can't test my question since I'm only 17, but It would be nice for someone to tell me so I can get it off of my mind.
I also wonder, if special relativity doesn't apply to other waves, then how do we know it does to light? Would we notice a change in 30 mph added to lights speed already?

2007-02-25 16:53:29 · 3 answers · asked by Michael 1

... before the stove had time to provide more heat

2007-02-25 16:52:04 · 2 answers · asked by chica1012 2

I know you are supposed to use the equation F=(G)(m1)(m2)/r^2 (I think?) but I don't know why I am getting some WEIRD numbers...thanks a lot =)

Two 270 kg (600 lb) masses are separated by a distance of 9 m. Using Newton's law of gravitation, find the magnitude of the gravitational force exerted by one mass on the other.

2007-02-25 16:26:03 · 1 answers · asked by Stephanie C 1

Can anyone tell me exactly how someone figured that out.

2007-02-25 15:54:14 · 3 answers · asked by Anonymous

1g of hydrogen contains 6.02*10^23 atoms, each with one electron and one proton. Suppose 1g oh hydrogen is separated into protons and electrons, that the protons are placed at the Earth's north pole, and the electrons are placed at Earth's south pole. Find the magnitude of resulting compressional force on Earth. (The radius of earth is approximately 6.38*10^5m).

2007-02-25 15:46:19 · 2 answers · asked by J39P 1

You are taking a turn at 39m/s on a ramp with a radius of 29m.

2007-02-25 15:38:54 · 3 answers · asked by RhondaJo 2

2007-02-25 15:31:13 · 3 answers · asked by altpro9 2

2007-02-25 15:21:06 · 2 answers · asked by Anonymous

2007-02-25 15:20:54 · 2 answers · asked by Buck BUCK 2

Ok i know we all know about gravity. But we still don't know what is that thing inside earth that pulls us all like a magnet! Isn't that a sad fact that we are still quite oblivious to this fact. Knowing gravity's equation is not enough!

2007-02-25 15:04:38 · 10 answers · asked by A fan 4

Question: evaluate the equation E = L2/L1.

L1 = 48.5 cm and L2 = 51.5 cm. both measurements have +/- .05 cm of uncertainty.

My Approach: I have seen 2 methods, but i get differing answers. what is a good answer to this problem???

2007-02-25 15:01:57 · 2 answers · asked by Jimmy 3

1) A horizontal force is applied to a wooden box restin on a table top. As soon as the box begons to slide, the force of friction will (1) decrease (2) increase (3) remain the same

2) A constant unbalanced force od friction acts on a 15 kg mass mocing along a horizontal surface ti rest in 1.50 sec, what is the magnitude of the force of friction? (1) 10.0 N (2)100N (3) 147 N (4) 150 N

3) If a boat is moving along at constant speed it may be assumed that (1) a net force is pushing it foward (2) the sime of only vertical forces is zero (3) the buoyant force is greater than gravity (4) the sum of only horizontal forces is zero (5) the sum of all forces is zero

2007-02-25 14:54:08 · 1 answers · asked by Whats the Scoop? 2

2007-02-25 14:36:44 · 11 answers · asked by sigilwig44 1

a force of 531 at -40 degrees newtons is required to give a 160 kg mass an acceleration of 1.31 m/s^2 . what is the force produced by the kinetic friction? what is the coefficient of kinetic friction?

2007-02-25 14:27:22 · 2 answers · asked by judykharrison 1

a t=0 mins, the cruise ship had a velocity of +447 cm/s and was at x=513 km. the ship then acce;erated at a constant rate of 10 cm/s^2. find the distance the cruise ship traveled in 2 mins.

2007-02-25 14:21:51 · 3 answers · asked by mandy 1

A. it multiplies effort
B. it makes the resistance smaller
C. The effort force moves only a small distance to make the resistance force move a large distance

2007-02-25 14:21:17 · 1 answers · asked by Anonymous

If any one was to send a bomb into space orbit
and it exploded over us what would happen????

2007-02-25 14:14:15 · 2 answers · asked by andhisson 1

a block that has a mass of 24 kg is initially at rest on an inclined plane of 25 degrees. (a) find the component of the weight that is parellel to the plane. (b) find the componentof the weight that is perpendicular to the plane. (c) find the maximum find the maximum force of static friction if the coefficient of static friction is .65. will the block slide down the plane?

2007-02-25 14:11:22 · 2 answers · asked by mandy 1

a .2 kg ball was released from a height of 10 meters. the ball hit the ground and rebounded to a height of 9 meters. (a) what was the vertical velocity of a ball just before it hit the ground? (b) what was the vertical velocity of the ball when it left the ground? (c) the collision w/ the ground was inelastic because kinetic energy was lost. how much energy was lost to heat and sound in the collision w/ the ground?

2007-02-25 14:07:48 · 2 answers · asked by mandy 1

2007-02-25 13:59:55 · 5 answers · asked by Tim H 1

2007-02-25 13:51:08 · 2 answers · asked by Tim H 1

2007-02-25 13:49:59 · 1 answers · asked by medway1234567 1

any help would be appreciated

2007-02-25 13:44:25 · 3 answers · asked by Eric 1

a single food CALORIE is enough energy to raise 1.0 kg how high?

I already found that work equals the
calories multiplied by 4.186 J/cal
calories will be 1000 cal... W = 4186 J
W=mgh
4186= (1kg)(9.8 m/s^2)h
i got h = 427.14

2007-02-25 13:40:49 · 2 answers · asked by ARE JAY 1

A 1.50 kg box slides down a rough incline plane from a height h of 1.03 m. The box had a speed of 2.77 m/s at the top and a speed of 2.34 m/s at the bottom. Calculate the mechanical energy lost due to friction (as heat, etc.).

2007-02-25 13:35:42 · 1 answers · asked by Anonymous

Imagine an aluminum bar encircling the earth. If the bar temperature increases by 1 degree fahrenheit, how high off the ground would the bar be if the entire bar is at that height? Assume a perfectly spherical earth.

2007-02-25 13:35:39 · 2 answers · asked by ARE JAY 1