Answer:
The optimum wavelength = (8.863 × 10⁻⁷) m = 886.3 nm
Explanation:
The light that will generate the photovoltaic energy of 1.4 eV will must have that amount of energy
Energy of light waves is given as
E = hf
h = Planck's constant = (6.626 × 10⁻³⁴) J.s
f = Frequency of the light
The frequency is then further given as
f = (c/λ)
c = speed of light = (3.0 × 10⁸) m/s
λ = wavelength of the light = ?
E = (hc/λ)
λ = (hc/E)
Energy = E = 1.4 eV = 1.4 × 1.602 × 10⁻¹⁹ = (2.2428 × 10⁻¹⁹) J
λ = (6.626 × 10⁻³⁴ × 3.0 × 10⁸)/(2.2428 × 10⁻¹⁹)
λ = (8.863 × 10⁻⁷) m = 886 nm
Hope this Helps!!!
 
        
             
        
        
        
Answer:
6.86 × 10²⁴ kg
Explanation:
The mass of the earth m = density of earth, ρ × volume of earth, V
m = ρV
The density of the earth, ρ = 5515 kg/m³ and since the earth is a sphere, its volume is the volume of a sphere V = 4πr³/3 where r = radius of the earth = 6.67 × 10⁶ m
Since m = ρV
m = ρ4πr³/3
So, substituting the values of the variables into the equation for the mass of the earth, m, we have
m = 5515 kg/m³ × 4π(6.67 × 10⁶ m)³/3
m = 5515 kg/m³ × 4π × 296.741 × 10¹⁸ m³/3
m = 5515 kg/m³ × 1189.9639π × 10¹⁸ m³/3
m = 6546105.64378π × 10¹⁸ kg/3
m = 20565197.400122 × 10¹⁸ kg/3
m = 6855065.8 × 10¹⁸ kg
m = 6.8550658 × 10²⁴ kg
m ≅ 6.86 × 10²⁴ kg
 
        
             
        
        
        
Answer:
 q = 2.65 10⁻⁶ C
Explanation:
For this exercise we use Coulomb's law
         F = 
 
In this case they indicate that the load is of equal magnitude
        q₁ = q₂ = q
the force is attractive because the signs of the charges are opposite
        F =  
        q =  
we calculate
         q =  
         q =  Ra 7 10-12
Ra 7 10-12
         q = 2.65 10⁻⁶ C