Which of the following statements is/are NOT correct ?

I. Force per unit volume is called pressure.

II. Liquids can exert pressure on walls of containers.

III. Force acting on an object can cause a change in it state of motion but not its shape.

Only III

The correct answer is option 2. Only III.

The statement that is NOT correct is Only III.

I. Force per unit volume is indeed called pressure. This statement is correct.

II. Liquids can exert pressure on walls of containers. This statement is also correct. Liquids, like gases, exert pressure on the walls of their containers due to the continuous collision of their molecules with the container walls.

III. Force acting on an object can cause a change in its state of motion and also its shape. This statement is incorrect. A force acting on an object can cause both changes in its state of motion (acceleration or deceleration) and its shape (deformation). For example, when you push or pull an object, you can change its shape as well as its motion.

So, the correct choice is Only III