Science & Mathematics - 28 October 2007

how to solve
x^3 - 8x^2y^2 + y = 9x?

2007-10-28 03:17:57 · 3 answers · asked by a s 2 in Mathematics

monochromatic light of wavelength 3.80 x 10-7m falls with an intensity of 6.0 x 10-6 W m-2 on to a metallic surface whose work function is 3.2 x 10-19J.

a) calculate the energy of a single photon of light of this wavelength
b) the number of photons emmited per second from 1.0 x 10-6 m2 of the surface if a photon has a 1 in 1000 chance of ejecting an electron.

please show me how to do it and not just give me the answer

2007-10-28 03:11:11 · 1 answers · asked by Ricky L 1 in Physics

Determine all the asymptotes and all the incercepts (both x and y) of the rational function

F(x)= (2x^2 - 2) / (x^2 - 9).

and

F(x)= (x^2 - x +3) / (x+1)

2007-10-28 03:10:17 · 3 answers · asked by K Rose 3 in Mathematics

2007-10-28 03:09:04 · 2 answers · asked by sunil s 1 in Astronomy & Space

2007-10-28 03:08:11 · 7 answers · asked by sairam_car 1 in Other - Science

2007-10-28 03:07:42 · 19 answers · asked by pinkbell11 1 in Other - Science

Can someone tell me what is the order of operations for this problem?
11-10 divided by (10x9) =

2007-10-28 03:02:31 · 16 answers · asked by Anonymous in Mathematics

2007-10-28 03:00:42 · 5 answers · asked by akram n 1 in Botany

Would other beach-goers, surfers, swimmers, saltwater alligators, sea cucumbers and other living things in the sea all around the world be electrocuted too or would it just affect a small area.

If so, how do you determine this area?

2007-10-28 02:52:02 · 2 answers · asked by Six 1 in Physics

2007-10-28 02:48:41 · 8 answers · asked by Rangarajan R 4 in Engineering

erature of both solution was 20.2 degree C before mixing and 26.3 degree C after mixing. the heat capacity of the calorimeter is 12.1 J/k. from these data calculate delta H for the process.
CuSo4(1M) + 2KOH(2M) to form Cu(OH)2(s) + K2So4(0.5 M)

2007-10-28 02:48:24 · 1 answers · asked by Anonymous in Chemistry

Low-voltage lighting is a popular feature of landscaping. Two pathways meet at 30 degrees to each other. One pathway has the lighting, and the first light is placed where the two paths meet. The distance between successive lights is 5m, and each has a range of effective illumination of 6m. For the second pathway, find, to the nearest tenth of a metre, the length that is
a.) effectively illuminated
b.) effectively illuminated by both the second and third light
c.) effectively illuminated by the third or fourth light.
Please show all workings.

2007-10-28 02:45:56 · 1 answers · asked by Anonymous in Mathematics

end to reach the speed of light?

degrees= 360
time= 1 sec
length= ?

*no air resistance or gravity

2007-10-28 02:42:33 · 6 answers · asked by tat6504 2 in Physics

1)the lengths of the tangents from the potint (4,k) to the circle x^2 + y^2 = 9 are 4sqroot2. find the possible values of the constant k.

i think the answer is + or - 5 but am unsure on the working

2) show that the tangents from the point (3,-4) to the circles x^2 + y^2 + 2x - 4y + 4 = 0 and x^2 + y^2 +4x - 4y -2 =0 are equal in length

2007-10-28 02:38:27 · 2 answers · asked by Anonymous in Mathematics

2007-10-28 02:37:15 · 7 answers · asked by Daniel_Walton 3 in Other - Science

2007-10-28 02:35:22 · 5 answers · asked by sk8er g 2 in Earth Sciences & Geology

2007-10-28 02:34:08 · 7 answers · asked by Anonymous in Other - Science

I have heard there was "something" up there...scared the c*** outta them so they legged it and never came back!

2007-10-28 02:33:03 · 8 answers · asked by westieforbobby 2 in Astronomy & Space

cos2x=7sinx-3

2sin^2x=3cosx

Solve the folowing 0 2sin3x= -sq root 3

2007-10-28 02:32:02 · 1 answers · asked by cait 2 in Mathematics

2007-10-28 02:31:09 · 5 answers · asked by Anonymous in Mathematics

2007-10-28 02:31:06 · 8 answers · asked by Re 1 in Physics

2007-10-28 02:17:27 · 4 answers · asked by GORAWALIA SHAH 1 in Physics

w.r.t x

a)
y = 16^(x^2 + 2x - 5) = (2x + 2)16^(x^2 + 2x - 5)ln(12)

b)
f(t) = 600,000e^(.4(sqrt(t))

t = time

at what rate is this function growing when t=8?

f(8) = 600,000(-.4)e^(.4sqrt(8))ln(e)
f(8) = 600,000(-.4)e^(1.13)

would this be correct? id appreciate any help/comments on this. thanks.

2007-10-28 02:08:59 · 1 answers · asked by Mathema-what?! 1 in Mathematics

A 135.0 kg box is pushed by a horizontal force F at constant speed up a frictionless ramp which makes an angle of 23.0 deg with the horizontal. What is the magnitude of the Normal force between the ramp and the box?

**I found the magnitude of the applied force=561.6 N. For some reason, I can't get the right answer on what the normal force is. If someone could help me that would be great!

2007-10-28 02:04:56 · 2 answers · asked by Anonymous in Physics

2007-10-28 02:03:24 · 7 answers · asked by Anonymous in Engineering

I have a graph which shows how the pH changes when 0.12M NaOH is added to 25cm³ of a solution of weak monoprotic acid HA. The graph shows pH/volume of NaOH.

I'm asked to calculate the intial concentration of HA. Does [H+] = [HA]? If so, I found it to be 0.02.

I'm also asked to determine the volume of NaOH when [HA] = [A-] but I don't know how to do this. Can anyone help me?

2007-10-28 01:57:58 · 1 answers · asked by Anonymous in Chemistry

Super hearing, super strength. extensive speed etc. can the human body achieve such things and more in anyway?

2007-10-28 01:55:47 · 5 answers · asked by D Bate A Bull 3 in Biology

The displacement 's' metres at time 't' seconds is given by:

s = 5cos3t + t^2 + 10 , for t => 0

a) Write doen the minimum value of 's'.

b) Find the acceleration, 'a', at time 't'.

c) Find the value of 't' when the maximum value of 'a' first occurs.

2007-10-28 01:55:32 · 2 answers · asked by Anonymous in Mathematics

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