A ship moves from west to east at a speed of 20 knots

Establish a coordinate system, with point A as the origin, the ship's course as the x-axis (east is the positive direction), and the typhoon's course as the y-axis (south is the positive direction).

Suppose that at time t, the ship encounters a typhoon.

The position of the ship is x=20*t

(y≡0)

The position of the typhoon is y=100-40*t

(x≡0)

Encounter conditions: (20*t)?+(100-40*t)?=(20√10)?

Obtain: t=1 hour.

So if the ship continues to sail at its original speed from point A, it will encounter a typhoon on the way. The typhoon encounter time is 1 hour later.