Answer:
F=126339.5N
Explanation:
to find the necessary force to escape we must make a free-body diagram on the hatch, taking into account that we will match the forces that go down with those that go up, taking into account the above we propose the following equation,
Fw=W+Fi+F
where
Fw= force or weight produced by the water column above the submarine.
to fint Fw we can use the following ecuation
Fw=h. γ. A
h=distance
γ=
specific weight for seawater = 10074N / m ^ 3
A=Area
Fw=28x10074x0.7=197467N
w is the weight of the hatch = 200N
Fi is the internal force of the submarine produced by the pressure = 1atm = 101325Pa for this we can use the following formula
Fi=PA=101325x0.7=70927.5N
finally the force that is needed to open the hatch is given by the initial equation
Fw=W+Fi+F
F=Fw-W+Fi
F=197467N-200N-70927.5N
F=126339.5N
By wave particle duality.
Wavelength , λ = h / mv
where h = Planck's constant = 6.63 * 10⁻³⁴ Js, m = mass in kg, v = velocity in m/s.
m = 1kg, v = 4.5 m/s
λ = h / mv
λ = (6.63 * 10⁻³⁴) /(1*4.5)
λ ≈ 1.473 * 10⁻³⁴ m
Option D.
The correct answer to the question is- 
CALCULATION:
As per the question, the electric field generated by the source charge is 1236 N/C at a distance of 4 m.
Hence , electric field E = 1236 N/C.
The distance of the point R = 4m
We are asked to calculate the charge possessed by the source.
The electric field produced by a source charge of Q at a distance R is calculated as -
Electric field E = 
Here,
is called the absolute permittivity of the free space.
Hence, the charge of source is calculated as -
Q = 
= 
= 
= 
= 
Hence, the charge of source is 
Faster than. Hope this helps!!!
Answer:

Explanation:
You can consider that the force that acts over the proton is the same to the force over the electron. This is because the electric force is given by:


where E is the constant electric field between the parallel plates, and is the same for both electron and proton. Also, the charge is the same.
by using the Newton second law for the proton, and by using kinematic equation for the calculation of the acceleration you can obtain:

(it has been used that vp^2 = v_o^2+2ad) where d is the separation of the plates, ap the acceleration of the proton, vp its velocity and mp its mass.
By doing the same for the electron you obtain:

we can equals these expressions for both proton and electron, because the forces qE are the same:
