Science & Mathematics - 12 September 2007

A particle's circular motion in the x-y plane is given by the equations: r(t) = 4.86m, theta(t) = (9.96rad/s)t, where r is the distance from te origin and theta is the polar angle measured counterclockwise from the positive x-axis. What is the x-coordinate of the particle at time t = 3.40s?

2007-09-12 16:18:17 · 2 answers · asked by Anonymous in Physics

Factor each polynomial by grouping the first two terms and the last two terms. x^3-4x^2+2x-8

2007-09-12 16:16:55 · 4 answers · asked by Anonymous in Mathematics

2007-09-12 16:14:45 · 12 answers · asked by Anonymous in Mathematics

2007-09-12 16:14:36 · 4 answers · asked by Anonymous in Mathematics

the same thing applies for earths mantle. the same thing is happening there. warm lava near the bottom is rising up because when heated density is lower and when lava is at the top it is cooler so it is more dense and falls back down. what i need to know is the name applied for this kind of cycle of change.

and if you can, can you tell me how earths mantle is different from a lava lamp???

2007-09-12 16:13:04 · 5 answers · asked by ~~xx{Stelth[k9]}xx~~ 1 in Earth Sciences & Geology

Is earth's wobble the cause of ice ages here?

2007-09-12 16:11:13 · 4 answers · asked by Anonymous in Astronomy & Space

2007-09-12 16:09:35 · 2 answers · asked by Anonymous in Mathematics

A ranger in a national park is driving at 54 km/h when a deer jumps onto the road 55 m ahead of the vehicle. After a reaction time of t s, the ranger applies the brakes to produce an acceleration of -3 m/s2. What is the maximum reaction time allowed if the ranger is to avoid hitting the deer?

* i got 40 sec. but the answer was wrong.. i don't get it.

2007-09-12 16:07:33 · 3 answers · asked by wonderer 1 in Physics

An empty Erlenmeyer flask weighs 264.3 g. When filled with water (d = 1.00 g/cm3), the flask and its contents weigh 500.3 g.

a) What is the flask's volume?

b) How much does the flask weigh when filled with chloroform (d = 1.48 g/cm3)?

2007-09-12 16:07:15 · 4 answers · asked by Anonymous in Chemistry

How do i use the definition of the derivititve to find f(x)= x + sqrt (x)

2007-09-12 16:05:50 · 3 answers · asked by Christine N 1 in Mathematics

A sports car is advertised to be able to stop in a distance of 50 m form a speed of 90 km/h. What is its acceleration in m/s^2. How many g's is this (g=9.80 m/s^2).

2007-09-12 16:02:53 · 1 answers · asked by nirmal 1 in Physics

Express 74.26' in degrees, minutes, and seconds to the nearest second

The answer is 74 degrees, 15 minutes, 36 seconds but I don't know how to get to there

2007-09-12 16:02:25 · 5 answers · asked by Anonymous in Mathematics

2007-09-12 15:59:59 · 6 answers · asked by dantistryfiliya 2 in Other - Science

2007-09-12 15:59:37 · 3 answers · asked by hanna 1 in Mathematics

2007-09-12 15:58:13 · 3 answers · asked by aimee 1 in Weather

Factor each of the following polynomials completely -3s^2-10x+8

2007-09-12 15:57:10 · 4 answers · asked by Anonymous in Mathematics

24-5d=d

i've been on this problem 4ever!!!
plz help1

2007-09-12 15:56:12 · 5 answers · asked by Anonymous in Mathematics

2007-09-12 15:55:32 · 2 answers · asked by Anonymous in Mathematics

A diver springs upward with an initial speed of 2.44 m/s from a 3.0-m board. (a) Find the velocity with which he strikes the water. [Hint: When the diver reaches the water, his displacement is y = -3.0 m (measured from the board), assuming that the downward direction is chosen as the negative direction.] (b) What is the highest point he reaches above the water?

2007-09-12 15:53:33 · 3 answers · asked by lonelygirlinhell 1 in Physics

Is it possible for 2 people with O positive blood to conceive a child that has O negative blood?

2007-09-12 15:53:11 · 5 answers · asked by Angel girl 4 in Medicine

If EF= 2x-12, FG= 3x-15, and EG = 23, find the values of x, EF, and FG.

x= ?
EF= ?
FG=?

2007-09-12 15:52:00 · 4 answers · asked by Anonymous in Mathematics

help

2007-09-12 15:51:35 · 2 answers · asked by SMD8 1 in Astronomy & Space

For example.....how do you simplify the number 28. What are the steps you take?

2007-09-12 15:51:24 · 4 answers · asked by pebbles11388 2 in Mathematics

2007-09-12 15:48:34 · 12 answers · asked by Barbie d 1 in Weather

I'm having surgery this week, and I'm having bad cramping. The hospital papers say not to take Moltrin or ASA for 1 week prior to surgery. What can I take for the pain?

2007-09-12 15:48:31 · 11 answers · asked by Nerds Rule! 6 in Medicine

I'm having horrible trouble with these questions.

1. Prove that if n is a perfect square, then n+2 is not a perfect square.
2. Prove that if n is a positive integer, then n is even if and only if 7n+4 is even.
3. Prove that either 2x10^500 + 15 or 2x10^500 + 16 is not a perfect square.
4. Prove or disprove that if a and b are rational numbers, then a^b is also a rational number.
5. Find a counterexample to the statement that every positive integer can be written as the sum of squares of three integers.

Really, it's been YEARS since I've had a math course before, and I really haven't the slightest idea of even where to start any of these... I'm not asking for a full proof for everyone, but just where I should start and the direction I should go from there...

2007-09-12 15:46:09 · 4 answers · asked by Anonymous in Mathematics

8+(3x+y)i=2x-4i

find the values of "x" and "y" that make the equation true.

("i"=the square root of -1)


how would i be able to solve this problem, there are two variables and only one equation


thank you :)

2007-09-12 15:45:10 · 1 answers · asked by jrfisher8 2 in Mathematics

A motorcycleist is going to try to jump across as many buses as he can. The takeoff rampy-thing makes an angle = 18.4 degrees above the horizontal.The landing ramp is identical to the takeoff ramp. The buses are parked side by side, and each bus is 2.74 m wide. The dud leaves the ramp with a speed of v = 31.0 m/s. What is the maximum number of buses over which the guy can jump?

i am so confussed and i have no idea how to do this!!!!!! i just don't even know where to start. please help me. i really am trying and im tired and i need to know how to do this last problem. i have finished the rest of my physics problems and i am just stumped! please help me. Thank you so much!!!!!!!!!!!!

2007-09-12 15:44:44 · 3 answers · asked by Elizabeth 3 in Physics

Exactly where in the fossil record is the evidence for progressive evolution (I've seen it stated a number of times on here that there is evidence), of actual transitional forms between major groups?

2007-09-12 15:44:22 · 7 answers · asked by BERT 6 in Astronomy & Space

I think I heard of such a thing but I'm not sure.

2007-09-12 15:44:21 · 9 answers · asked by Anonymous in Botany