If water can be sprayed on every inch of soil, the effective range of this device with a range of 10 m is about 14. 14 m (the inscribed edge of a circle with a radius of 10 m is 10 times the square with the root number 2, which is about 14 m).

400/ 14. 14 ≈ 28

350/ 14. 14 ≈ 25

28 ×25 = 700!