Science & Mathematics - 11 October 2007

The cells of which of these organs undergo aerobic respiration?
a. heart
b. lungs
c. skin
d. kidneys
e. all of these
I THINK b

2007-10-11 12:42:24 · 3 answers · asked by Anonymous in Biology

explain in detail

2007-10-11 12:42:20 · 2 answers · asked by Macgyver with Crosby 4 in Earth Sciences & Geology

1. 111[]
2. 159[]
3. 21[]
4. 69[]

2007-10-11 12:41:24 · 2 answers · asked by dilljam1977 1 in Mathematics

A 115 x 10-6 F capacitor is connected to an ac generator with an rms voltage of 15.9 V and a frequency of 154 Hz. What is the rms current in this circuit?

The rms current is A.


Please explain, thanks!

2007-10-11 12:36:17 · 1 answers · asked by Anonymous in Physics

Consider a force of 62.4N pulling 3 blocks of identical masses, where each mass is 1kg, along a rough horizontal surface. The coefficient of kinetic friction is 0.8. The accel of gravity is 9.81m/s^2.
- What is the acceleration?


-The tension of the strings are T1 and T2. The equation of motion m2 is given by what ?
a) T1-μ m2g = m2a
b) T1-T2 + μ m2g - μ m1g = m2a
c) T1 + μ m2g = m2a
d) T1- T2 - μ m2g = m2a
e) T1 - T2 + μ m2g = m2a
f) T1 + T2 - μ m2g = m2a
g) T1 + T2 - μ m2g - μ m1g = m2a.

Please Help, I thought I figured it out - but was wrong..thanks

2007-10-11 12:35:12 · 1 answers · asked by Anonymous in Physics

Why some doctors who get great grades in med school end up being incompetent? is there a secret of diagnosing patients?

2007-10-11 12:33:05 · 4 answers · asked by dk 6 in Medicine

the doubling period of a bacterium is 20 mins. If there are 300 bacteria in a culture initially, how many bacteria will be there be after in 1 hour?

2007-10-11 12:28:21 · 2 answers · asked by Anonymous in Biology

please :] i REALLY need help

2007-10-11 12:27:41 · 4 answers · asked by michelleee 1 in Biology

Describe the locus of points whose coordinates satisfy both statements:
x2 + (y – 2)2 = 25
y < 0

the part of the circle with center (0, 2) and radius 5, on or below the x-axis
the part of the circle with center (0, 2) and radius 5, below the x-axis
the part of the circle with center (0, -2) and radius 5, on or to the left of the y-axis
the part of the circle with center (0, 2) and radius 5, to the left of the y-axis

2007-10-11 12:26:08 · 1 answers · asked by Anonymous in Mathematics

We are doing a project/debate on the topic "That animals should not be caged in zoos for human entertainment." We are on the negative side. We are asking you to give your honest opinion on this question. We are going to look at the answers that you give us and then look at the majority at the answers and use them in our debate.

Thanks if you answer this.

2007-10-11 12:25:45 · 15 answers · asked by E F 2 in Zoology

2007-10-11 12:24:14 · 3 answers · asked by Anselmo III A 1 in Earth Sciences & Geology

Box 1 of mass m1=5.0kg starts from rest in point A and slides down a frictionless ramp of height h=0.50m. In point B, the surface becomes horizontal and rough, with a coefficient of kinetic friction u=0.1. In point B, Box 1 collides head-on elastically with the stationary Box 2 of mass m2=7.0kg. After collision, the Box 1 slides back up on the ramp, and Box 2 travels a horizontal distance d=0.50m. In point C, Box 2 hits a long spring with elastic constant k=350 N/m. The spring is compressed by the incoming box (the surface under the spring is frictionless).

a) Calculate the speed, VB, of Box 1 at the base of the ramp, just before the collision.
b) Calculate the velocities of the two boxes immediately after the head-on elastic collision.
c) How high up the incline does Box 1 climb after the collision?
d) What is the kinetic energy of Box 2 immediately before striking the spring?
e) Calculate the maximum compression of the spring.

2007-10-11 12:23:36 · 2 answers · asked by snow200098 2 in Physics

2007-10-11 12:20:05 · 3 answers · asked by Anonymous in Earth Sciences & Geology

http://i40.photobucket.com/albums/e215/xxs3xp1stolxx/3.jpg

2007-10-11 12:19:26 · 1 answers · asked by Ant J 1 in Mathematics

http://i40.photobucket.com/albums/e215/xxs3xp1stolxx/2.jpg

2007-10-11 12:18:03 · 9 answers · asked by Ant J 1 in Mathematics

2007-10-11 12:15:27 · 4 answers · asked by katgirl0306 1 in Astronomy & Space

A baseball diamond has the shape of a square with sides 90 feet long. A player hits the ball and runs toward first base with a speed of 24 feet per second. At what rate is the player’s distance s from third base changing when the player is halfway to first base?

someone please explain this in a way thats easy to understand!
:]

2007-10-11 12:15:13 · 1 answers · asked by katuhstrahfik 1 in Mathematics

I have a couple of questions on relative motion
1. Two swimmers can swim equally fast relative to the water. they have a race to see who can swim across a river in the least time. Swimmer A swims perpendicular to the current and lands on the far shore downstream, because of the current. Swimmer B swims upstream at an angle to the current and lands on the shore directly opposite the starting point. Wo crosses the river in the least time. Explain your answer.

2. A ball is whirled on the end of a string in a horizontal circle of radius R and period T. If the period is increased by a facotr of 2 (keeping the radius constant), what speed must you have in the comparison to the original speed to maintain the same centripetal acceleration as before.

Any help will be much appreciated.

2007-10-11 12:09:10 · 2 answers · asked by Apoorva K 1 in Physics

Can any events that happen outside our solar system affect us on earth?

A supernova would be a bright light in the sky but would it be harmful in any way? Are there any other interstellar events that might be harmful to the earth?

2007-10-11 12:07:42 · 7 answers · asked by Jeffrey K 7 in Astronomy & Space

2007-10-11 12:04:52 · 12 answers · asked by Asia 3 in Biology

I was assigned a science project just last week. I have to get 2 of the same plants and water one with salt water and the other with fresh water. I need a hypothesis. I think that the plant without salt will grow taller. My brother told me that is true, because the salt displaces the water. But i need to know if this info is correct, and what i should put in my hypothesis. I am really, really stuck!

If you have any other ideas, please tell me what you think my hypothesis should be!!!!

2007-10-11 12:01:46 · 1 answers · asked by Anonymous in Other - Science

Given the circle (x – 6)2 + (y + 2)2 = 9, determine if the line with an equation of 3x – 2y = 12 is a tangent to the circle, a secant to the circle, or neither.

tangent
secant
neither

2007-10-11 12:01:19 · 1 answers · asked by Ant J 1 in Mathematics

When I was younger I lived in a haunted house. To give you an idea of why I said its haunted, there was sometimes boots stomping up and down the stairs late at night, my mother saw a woman in a night gown fade away, my father saw a tiny child's rocking chair rock back and forth for about 2-3 min. There was no breeze or anything to make the chair rock.

I didn't witness any of these things happen, but ever since we had moved into the old two story house I had nightmare like dreams. Basically, in the dream it would be pitch black and there would be faces laughing hysterically non-stop, pure insanity. It happened almost every single night after I went to sleep and it was always the same dream with the same details. After we moved, the nightmares stopped.

2007-10-11 11:54:36 · 11 answers · asked by Anonymous in Paranormal Phenomena

2007-10-11 11:52:38 · 2 answers · asked by Marissa 1 in Biology

Disclaimer: I'm not trying to cheat or anything, I just need a few of these problems done with work shown and explained to me.

1)What is the length of a light-year in meters?

2)How many years and seconds does it take light to travel from the star Alpha Centauri to Earth? (25.8 trillion miles away)

3)Approximatly 4x10^9 kg of matter is converted to energy in the sun each second. At this rate how long should it take to have all of the suns energy converted to mass? (I don't know what you need to know in terms of what is necessary to complete this problem, but there is a lot of numbers about it on wikipedia ie. volume etc...)

4)How many kms in one parsec? How many light-years

Okay, last one

5) Suppose you have a mass of 70 kg on Earth. How much would you wigh in pounds and Newtons on the surface of a white dwarf star, the same size as Earth, but having a mass 300,000 times that of Earth (nearly the mass of the sun)?

Okay, thats it, I'm going to post this in 2 places.

2007-10-11 11:52:35 · 3 answers · asked by Anonymous in Astronomy & Space

I am doing a project on orange trees and need help on this fact. Also how does it support them? thank you so much. This is urgent, due TOMORROW. Thank you so much far understanding and answering.

2007-10-11 11:48:11 · 2 answers · asked by KayleeR 3 in Botany

how do you figure out what the speed of light is in a substance? i need the speed of light in a substance to use in the equation n=c/v to figure out n (index of refraction) cause all i have is c. idk how to figure out the speed of light in the substance...im guessing i have to use another eqation? does it have to do with Snells law? i just dont know, please enaswer and explain if you can.

Here is another question:
a 60 watt light bulb is located 10m away from a 2m by 3m wall. the light intensity on the wall is 1900 lux use the inverse suare law to find the intensities if the distance is change to 20m 30m and 40m.
-i kinda get the inverse square law liek if it is double the distance away you take the inverse fo 2 ( which whould be 1/2) and square it but...i had a practice problem JUST like this with different numbers and i got it wrong ann i know im missing somethingg?? idk what though. please help and explain<333 thank you

2007-10-11 11:46:30 · 2 answers · asked by Anonymous in Mathematics

2007-10-11 11:45:46 · 1 answers · asked by Richard S 3 in Physics

My latest attempt to understand the big bang theory: so if all the matter was in this tiny space...wouldn't it all condense to form a black hole...you know the process of gravitational collapse.

*sigh* if only I took physics as a major in college......

2007-10-11 11:45:42 · 6 answers · asked by Sam 6 in Astronomy & Space

A certain frog's hind legs produce a force of 2.5 times its weight through a vertical distance of 9 cm, at which point the frog becomes airborne. A) What is the frog's speed at takeoff? B)What height about the ground does the frog reach?

the answers are 1.63 m/s and 13.5 cm

Please help me and show me how to do this
thanks!!

2007-10-11 11:44:46 · 1 answers · asked by J 2 in Physics