BRUCE's Responses in WyzAnt Answers

Prasenjeet,

The problem is :   49/(49000*1.660*10-27)=6.022*10^23

Use scientific notation & simplify:

49/(49*10^3 * 1.660 * 10^-27)=  

1/(10^3 * 1.660 * 10^-27)

1/(1.660 * 10^-24) =

(1/1.660)*10^24 =

6.024 * 10^23

Note:  The original problem has a most 2 significant digits (ie 49) so the answer should be reduced to 2 significant digits also:

6.0 * 10^23

BruceS

Sherry,

  This is like 'Algebra Jeopardy'....Given the answer, what is the question!?

For a quadratic equation like x^2 + b*x + c =0 you end up with factoring usually like this:

(x+w)(x+z)=0

The the roots are x = -w, -z

The problem gives the roots  -w and -z so now just subsitute:

-w = -3  and -z = 5

The factored equation is:

(x+3)(x-5) = 0  or expanded it is:

Note: I have assumed a quadratic equation but there are many equaitons of other types with these roots.    For example:

x+3 =0    so x=-3

x-5 = 0  so x=5

(x+3)(x+3)(x-5) = 0  This is a third order polynomial with a double root:  x=-3

And so it goes...

BruceS

Hi Alex,

  An atom consists of a nucleus surrounded by a 'cloud' of electrons.  The nucleus is compose of protons and neutrons in most cases (Hydrogen only has a proton in the nucleus.)  Based on this description the nucleuos is part of the atom so the atom does not move around the nucleus.

  The question might be better stated as 'In an atom, how do electrons move around the nucleus?'  

This depends on what level of quantum mechanics you are using to describe the atom.  In the Bohr Model, created in the early 20th century, the electrons moved in disctinct orbits govern by electromagnetic forces between the nucluse (it has a net positve charge) and each electron (each has a negative charge).  As quantum mechanics progressed, the 'Heisenberg Uncertainty Principle' dictated that the momentum and position of a particle could not be simultaneously defined exactly (Δx * Δp ≥ h/2*Pi, where x = position, p=momentum, h= Planck's constant).  With this constraint the location and movement of an electron near the nucleus is 'uncertain'.  Thus physicists and chemists talk about an electron as being distributed around the nucleus...in a  'cloud'.  (No, not the cloud connected to your phone!  ;-)  )

   These two descriptions of the electron's behavior highlight two competing ideas in physcis:  Is the universe deterministic (like the Bohr model) or does the universe behave in a probabalistic manner (as decscribed by Heisenberg's uncertainity principle).

  Food for thought!

BruceS

Ruby,

   You can expand the square and rearrange into the standard form for a polynomial:

y-4=(x+2)^2

y-4= x^2 + 4x + 4

y = x^2 + 4x + 8

And then you can plot it.  Turns out to be a parabola, open upwards with a minimum at x=-2 and y=4.

Good Luck,

BruceS

Tina,

  Look at the answer to y=-x.

  again use the generic straight line formula and/or plot it!

Good Luck,

BruceS