Because the people in the car are attached to the vehicle, the people inside the vehicle are going the same speed as the vehicle.
Hope this helps! :)
To solve this problem we will begin by finding the pressure through density and average depth. Later we will find the Force, by means of the relation of the pressure and the area.

Here,
h = Depth average
= Density
Moreover,

Replacing,


Finally the force



Mechanical and Chemical. (Weathering and erosion)