Which object has more inertia and why? A car or a ship?
The ship, because it is more massive
Inertia and mass are interrelated. Heavier or massive objects offer larger inertia. Quantitatively, the inertia of an object is measured by its mass. We may thus relate inertia and mass as follows: Inertia is the natural tendency of an object to resist a change in its state of motion or of rest. The mass of an object is a measure of its inertia.
Since the ship is much heavier than the car, it offers more inertia.