What is the total energy transported per hour along a narrow cylindrical laser beam 1.80 mm in diameter, whose B-field has an rms strength of

Am assuming the  B-field has an rms strength of 1.10×10−10T which was omitted

 E=1.686 x10⁻⁸J/hr

Explanation:

Intensity for electromagnetic wave is given as

I= cε₀(Emax)² equation 1

Also

B=Emax/c   equation 2

puting the value of B in equation 2 in equation 1 becomes

I= cε₀(Emax)²

I= c³ε₀B²

where

c = speed of light = 3 X 10⁸m/s

ε₀=permittivity of free space =8.85x 10-12 F m-1

B=1.10×10−10T

I= (3 X 10⁸m/s)³ X (8.85 X 10⁻12F/m) x(1.10×10−10T)²

I=2.891 X 10⁻⁶ W/m²

Energy per unit hour

E= IAt

= 2.891 X 10⁻⁶ W/m² x πr²x 3600

2.891 X 10⁻⁶ W/m² x 3.142 x ( 1.80 x 10⁻³/2) x(3600/1hr)

E=1.686 x10⁻⁸J/hr

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz