# Inertia

## Would you like to delve deeper into the important physical concept of inertia?

The online inertia simulations on this page help us to better understand this concept and its implications.

Inertia is a fundamental property of matter that refers to 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 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 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.

## 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.

## 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.

## 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.