The energy of a photon is given by:

where h is the Planck constant and f is the photon frequency.
We know the energy of the photon,

, so we can rearrange the equation to calculate the frequency of the photon:

And now we can use the following relationship between frequency f, wavelength

and speed of light c to find the wavelength of the photon:
The answer to your question is Metal
As per the given Figure attached here we know that both charges q1 and q2 will apply same force on charge q3 and hence the resultant force due to both charges will be along Y axis vertically upwards
So here we know that

now from the above equation


so both of the charges will apply 0.288 N force on q3 charge along the line joining them
now the net force due to vector sum is given by

here we know that angle is

now we have


so net force on q3 is 0.46 N vertically upwards along +Y axis
Answer:
4.2 is the answer
Explanation
The image formed in a plane mirror is an equal distance behind the mirror as the object in front of it.
Step 1: the equation to this problem would be: 8.4/2
Step 2: 8.4 ÷ 2 = 4.2
Answer:
The nearest plant (A) receives 4 times more radiation from the farthest plant
Explanation:
The energy emitted by the star is distributed on the surface of a sphere, whereby intensity received is the power emitted between the area of the sphere
I = P / A
P = I A
The area of the sphere is
A = 4π r²
Since the amount of radiation emitted by the star is constant, we can write this expression for the position of the two planets
P = I₁ A₁ = I₂ A₂
I₁ / I₂ = A₂ / A₁
Suppose index 1 corresponds to the nearest planet,
r2 = 2 r₁
I₁ / I₂ = r₁² / r₂²
I₁ / I₂ = r₁² / (2r₁)²
I₁ / I₂ = ¼
4 I₁ = I₂
The nearest plant (A) receives 4 times more radiation from the farthest plant