The answer is c hope this helps
The seat belt is applying a force in the opposite direction.
I'll put my answer in the comments but, part of the question is cut off do you mind putting a more readable and not sideways picture?
Answer:
λ = 0.4 x 10⁻⁶ m = 400 nm
Explanation:
The relationship between frequency, wavelength and speed of an electromagnetic wave is given as follows:

where,
c = speed of light = 3 x 10⁸ m/s
f = frequency of the light wave = 7.5 x 10¹⁴ Hz
λ = wavelength of the light = ?
Therefore,

<u>λ = 0.4 x 10⁻⁶ m = 400 nm</u>
Answer:
The number of free electrons per cubic meter is 
Explanation:
It is given that,
The number of free electrons per cubic meter is, 1.3
Electrical conductivity of metal, 
Density of metal, 
Atomic weight, A = 107.87 g/mol
Let n is the number of free electrons per cubic meter such that,


Where
is the density of silver atom
is the Avogadro number
A is the atomic weight of silver


or

Hence, this is the required solution.