An iron rod with a mass m slides on parallel horizontal gold rails, a distance L apart, and carries a current of I. The coefficient of kinetic friction between the rod and rails is μ. What vertical, uniform magnetic field is needed to keep the rod moving at a constant speed? (Enter the magnitude. Use any variable or symbol stated above along with the following as necessary: g

The expression is

Explanation:

If the rod is move with constant velocity, the expression of the magnetic field is:

∑Fn = Fm - fk = 0

Where

B is the magnetic field

m is the mass

g is the gravity

I is the current

L is the distance

μ is the kinetic friction between the rod and rails

when it gains or loses electrons

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