Final answer:
The magnitude of Jonathan's displacement is 246.9 km
Step-by-step explanation:
To calculate the magnitude of displacement, we can use the Pythagorean theorem. The distance traveled due west is 240 km and the distance traveled due south is 57.0 km. We can represent these distances as legs of a right triangle. The displacement is then the hypotenuse of this triangle. Using the Pythagorean theorem, the magnitude of the displacement can be calculated as:
Displacement = sqrt(240^2 + 57.0^2) = sqrt(57600 + 3249) = sqrt(60849) = 246.9 km