Inertia and velocity are both concepts used in the study of physics, but they refer to different aspects of an object's motion.
Inertia: Inertia is the property of matter that describes its resistance to changes in motion. It is often associated with Newton's first law of motion, which states that an object at rest will remain at rest, and an object in motion will continue moving at a constant velocity unless acted upon by an external force. In simpler terms, inertia is the tendency of an object to "keep doing what it's doing." An object with a greater mass has greater inertia, meaning it is more resistant to changes in its motion.
Velocity: Velocity, on the other hand, is a measure of an object's speed in a specific direction. It is a vector quantity, meaning it has both magnitude (the numerical value representing the speed) and direction. Velocity describes how fast an object is moving and in which direction it is moving. For example, a car traveling at 60 miles per hour to the east has a velocity of 60 miles per hour in the eastward direction.
In summary, inertia refers to the resistance of an object to changes in its motion, while velocity describes an object's speed and direction of motion. Inertia is a property of matter, whereas velocity is a measure of an object's motion.