When can an electric field be measured at any point from the force on a stationary test charge at that point?

Electric field be measured at any point from the force on a stationary test charge at that point, when the force on the test charge is generated only by the coulomb field (E) of static charges.

Explanation:

Total force on a test charge is given as;

F = qE + q(V x B)

F = q(E + V x B)

Where;

F is the total force on the test charge

q is the test charge

E is the electric field

B is the magnetic field

V is the velocity of the test charge

F = q(E + V x B)

for a stationary test charge, V = 0

The equation above reduces to;

F = qE

Thus, electric field be measured at any point from the force on a stationary test charge at that point, when the force on the test charge is generated only by the coulomb field (E) of static charges.

their crystal patterns have been disrupted by stress

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