Two plumbers are working at a site. the first tries to unscrew a pipe with a wrench and cannot budge it. the second one is twice as strong as the first one. he also has a wrench that is twice as long. how much more torque can the second plumber exert compared to the first?

The second plumber can exert 4 times more torque than the first one.

Explanation:

Torque is the cross product of force which causes rotation and the distance from the axis of rotation at which the force is applied.

τ = F × r

For the first plumber,

τ₁ = F₁ × r₁

For the second plumber,

τ₂ = F₂ × r₂ = 2 F₁ × 2 r₁ = 4 F₁ × r₁ = 4 τ₁  (∵ second plumber is twice as strong as first and second wrench is twice the length of first)

⇒τ₂ = 4 τ₁

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