A remotely operated underwater vehicle is moving east in a straight line. The table shows all the horizontal forces acting on the vehicle before and after the water conditions change.
| Stage | Propeller force east / N | Water resistance west / N |
|---|---|---|
| Before the change | 460 | 460 |
| After the change | 460 | 620 |
Explain how the horizontal forces affect the motion of the vehicle before the water conditions change.
Calculate the resultant horizontal force on the vehicle after the water conditions change. Explain how this resultant force affects the motion of the vehicle immediately after the change.