An oil tanker is partially filled with oil and moves forward on a level road with uniform acceleration. The free surface of oil then

1 An oil tanker is partially filled with oil and moves forward on a level road with uniform acceleration. 2 Due to the forward acceleration (a), the oil experiences an inertial force (pseudo-force) acting backwards. 3 The free surface of oil will align itself perpendicular to the net force acting on it (vector sum of gravity downwards and inertial force backwards). 4 This results in the free surface becoming inclined to the horizontal. 5 The inertial force pushing the oil backwards causes the oil level to rise at the back and lower at the front. 6 Therefore, the surface will be inclined with a larger depth at the rear end.