Question

Find the distance travelled by the cutter relative to the water in the first case of the preceding problem. 

Answer 1

Answer: S₁ = 2.1km. 

Explanation:

When moving with the current, the cutter travels a distance

 S' = v₂t₂ = Sv₂/(v₂ + v₁) = 0.8km

relative to the water (see solution of the preceding example). When moving against the current,

 S" = v₂t₁ = Sv₂/(v₂ — v₁) ≅ 1.3km.

The total distance travelled by the cutter relative to the water is

S₁ = s' + S" = 2.1km.