Science & Mathematics - 20 December 2007

Alona told her son Frank to paint the fence. Frank whined and complained. So she said " OK, you dont have to do it today. Instead paint 1/2 of one board today. Tomorrow paint 1/3 of a board and 2/3 of a board. I dont care which board you paint. The next day paint 1/4 of a board, 2/4 of a board, and 3/4 of a board. That will cover 3 days; continue like that for another 22 days. I'll do the rest." If you add up all the boards Frank completed and the parts he painted, Frank paint the eqivalent of how many boards?



Be sure to answer with steps/ exlpanation

2007-12-20 10:48:33 · 4 answers · asked by frost breezy 2 in Mathematics

1.How might convection currents account for the movement of the continents?

2. How does plate tectonics explain the formation of mountains?

2007-12-20 10:48:16 · 3 answers · asked by Anonymous in Earth Sciences & Geology

i had 100 probs 2 do i did all but these 16

7. identify the decomposition of u into the sum of two orthogonal vectors. One of which is the projection of v onto u
u = {2,-1} v= {1,-5}

8. find zw
z= 8(cos pi/6 + i sin pi/6) w= 4(con pi/12 + i sin pi/12)

I think its 32(cos pi/4 + i sin pi/3)

9. find the direction angle of the vector
v= -3i -10j

10. identify the trigonometric form of the complex number
3 – 8i

11. find the number by which the components of the vector can be divided to find the unit vector in the same direction
u= -3i + 3j
12. a box being pulled by two ropes . one rope exerts 55lbs and force of 24 degrees the other rope exerts 95 lbs and a force of 23 degrees. Find the direction and magnitude of the resultant of two forces

13. find the value of the expression:
(cos30 degrees + i sin 30 degrees) / (cos 75 degrees + i sin 75 degrees)

2007-12-20 10:45:33 · 2 answers · asked by Anonymous in Physics

The condition of apparent weightlessness for the passengers can be created for a brief instant when a plane flies over the top of a vertical circle. At a speed of 250 m/s, what is the radius of the vertical circle that the pilot must use?

thank you

2007-12-20 10:43:52 · 1 answers · asked by Mr. Tambourine Man 3 in Physics

Is it possible to take a step somewhere and instantly walk into a different time?

2007-12-20 10:42:36 · 13 answers · asked by Anonymous in Astronomy & Space

Question 1: An m2 = 1.4 kg can of soup is thrown upward with a velocity of v2 = 5.2 m/s. It is immediately struck from the side by an m1= 0.5 kg rock traveling at v1= 8.2 m/s. The rock ricochets off at an angle of α = 65 degrees with a velocity of v3= 5.4 m/s. What is the angle of the can’s motion after the collision? Answer in units of degrees.

Question 2: With what speed does the can move immediately after the collision? Answer in units of m/s.

PLEASE HELP ME PEOPLE !!! THANK YOU

2007-12-20 10:41:52 · 1 answers · asked by Anonymous in Physics

Computer-controlled display screens provide drivers in the Indianapolis 500 with a variety of information about how their cars are performing. For instance, as a car goes through a turn, a speed of 205 mph and a centripetal acceleration of 3.7g (3.7 times the acceleration due to gravity) are displayed. Determine the radius of the turn (in meters).

2007-12-20 10:38:48 · 1 answers · asked by Mr. Tambourine Man 3 in Physics

2007-12-20 10:37:53 · 3 answers · asked by shy one 2 in Mathematics

2007-12-20 10:37:32 · 1 answers · asked by Anonymous in Botany

2007-12-20 10:37:17 · 36 answers · asked by Anonymous in Biology

x^2=7x-9

2007-12-20 10:36:10 · 5 answers · asked by shy one 2 in Mathematics

1)Calculate the force of gravity between a human adult (mass = 88 kg) and the planet Mars (mass = 6.4 *10^23 kg), when Mars is at its closest to Earth (distance = 8 *10^10 m).

2)Calculate the force of gravity on a 10 kg mass at Earth's surface. The mass of Earth is 6*10^24 kg, and its radius is 6.4 *10^6 m.

3)Calculate the force of gravity on a 19 kg mass if it were 6.4* 10^6 m above Earth's surface (that is, if it were 2 Earth radii from Earth's Center.) The mass of Earth is 6 *10^24 kg.

4)Calculate the force of gravity between a newborn baby of mass 4 kg and the obstetrician of mass 70 kg, who is 0.2 m from the baby.

2007-12-20 10:36:02 · 1 answers · asked by eaglesblueflag 1 in Physics

While watching water the thought came to mind...or are the bands stable radially?

2007-12-20 10:35:33 · 2 answers · asked by afriendof CLIFFy D 2 in Astronomy & Space

2007-12-20 10:35:15 · 7 answers · asked by Kimberly M 1 in Mathematics

please help

2007-12-20 10:33:33 · 2 answers · asked by Anonymous in Biology

what is the answer to this problem?

x to the 1/2 times y to the 1/3

is it x to the 3/6 and y to the 2/6
or do you combine the exponents and then its (xy) to the 5/6

i know if it were x to 3/6 times x to the 2/6 you add the exponents but idk what to do when there are two different variables

this is the only thing im confused on. thanks for the help

2007-12-20 10:31:07 · 3 answers · asked by damon1570 1 in Mathematics

please help

2007-12-20 10:30:45 · 3 answers · asked by Anonymous in Biology

A. true
B. false

2007-12-20 10:29:56 · 4 answers · asked by Anonymous in Biology

The length of the force vector is proportional to what property of a force?

Why is force not a scalar qusntity?

What happens to an object in motion when it experiences a nonzero net external force?

Why does it require much less force to accelerate a low-mass object than it does to accelerate a high-mass object the same amount?

How do mass and weight vary with altitude?

Distinguish between mass and weight

How does the force of static friction on a crate you cannot budge compare to the force you exert on it?
Assume that the crate is on a flat surface.

2007-12-20 10:28:32 · 1 answers · asked by AshleyAfinow 1 in Physics

A. true
B. false

2007-12-20 10:26:19 · 2 answers · asked by Anonymous in Biology

need help please

2007-12-20 10:26:07 · 1 answers · asked by Anonymous in Physics

Me and my friends are having a debate on if cloning can actually occur. Yes i know that they have cloned things before but what i want to know is if they have ever come up with real life that never existed before the cloning. Please give me information and facts. I myself never believe we will be able to make life. Because i believe in God and believe that he is the only one who can make life. If you agree with me please leav me the name of a website where i can learn more.

2007-12-20 10:21:06 · 3 answers · asked by Chelsea D 2 in Biology

2007-12-20 10:19:59 · 5 answers · asked by Jasmine 1 in Mathematics

Hi,
I have a problem. I dont remember how to caculate of numbers
Please help

How many guanines in a DNA molecule 1000 base pairs long if 20% of the molecules consist of adenines? Show your math and inclue a verbal explanation.

So I dont know how to do this. Please help me out

2007-12-20 10:18:09 · 6 answers · asked by Anonymous in Biology

2007-12-20 10:15:44 · 5 answers · asked by french_learner 1 in Botany

...the resistance due to the skin effect?

There are formulas to calculate both, but I don't know how the skin effect resistance works at low frequencies where the resistance due to the skin effect is less than the DC resistance. Do they add? Rdc + Rac? Is the AC resistance ever less than the DC resistance?

2007-12-20 10:15:16 · 1 answers · asked by flaxseedoilandbalm 2 in Physics

2007-12-20 10:14:33 · 2 answers · asked by arjay c 1 in Mathematics

2007-12-20 10:14:14 · 3 answers · asked by Kimberly M 1 in Mathematics

2007-12-20 10:14:13 · 6 answers · asked by dee 1 in Geography

ASAP

2007-12-20 10:12:35 · 5 answers · asked by Brittany w 1 in Biology