Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Inertia. Newton’s First Law

Would you like to better understand what inertia is and how it relates to other concepts in physics?

The online inertia simulations on this page help us to better understand the important concept of inertia in physics and its most significant implications.

The concept of inertia in physics

The concept of inertia in physics refers to a fundamental property of matter that consists of the tendency of objects to resist changes in their state of motion or rest. It is a central concept in physics and is related to Newton’s first law of motion, known as the law of inertia.

The concept of inertia. Newton’s first law or law of inertia

The law of inertia states that an object at rest tends to remain at rest, and an object in motion tends to maintain its velocity constant in a straight line unless an external force acts on it. This law is the basis of classical physics.

Inertia in physics. Applications in everyday life

Inertia manifests itself in various ways in everyday life. For example, when in an automobile and the driver brakes sharply, the occupants tend to continue moving forward because of their inertia. Similarly, when accelerating rapidly, the occupants are pushed backward because of their resistance to change from their resting state.

Inertia also explains why heavier objects require more force to move or stop than lighter objects. If a small object and a large object are pushed with the same force, the larger object will have a lower acceleration due to its greater inertia.

Inertia simulations

Acceleration and deceleration


In this animation we have two blocks on top of a cart on a frictionless surface. When the cart starts, the block on the left falls to the ground. When the cart stops, it is the block on the right that falls. Explain these results from the concept of inertia in physics.



Uniform motion


In this animation, a cart with a block on it is moving at a constant speed. Suddenly the block is thrown vertically, while the cart continues its motion. Can you explain what happens? What would happen if the mass of the block or the velocity of the cart were changed?


Suspended ball


In this simulation we have a truck carrying a ball suspended by a cable. See what happens when accelerations or decelerations are applied to the truck and when the truck moves with uniform velocity. How does it relate to the concept of inertia in physics?



Water tank


In this simulation we have a truck carrying a tank of water. See what happens to the surface of the water when accelerations or decelerations are applied to the truck and when the truck moves with uniform velocity.


Motion of an elevator


In this simulation we can see what happens to the compression balance readings as the elevator moves up and down. What does this have to do with inertia in physics?



STEM education equipment

Physics courses

You may also be interested

You may also be interested