If the vertical deflection of the electron as it leaves the plates is 9.00 mm, how much has its kinetic energy increased due to the electric field?

Explanation:

According to the work-energy theorem, the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle:

Work is defined as the product of the force acting on the particle, the displacement due to that force and the cosine of the angle between them:

The electric force on the electron is given by:

In this case since the electric force is negative, the displacement is in the same direction, that is, opposite to the direction of the electric field. Finally, we calculate how much has electron's kinetic energy increased:

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day