INERTIA

To explain the role of inertia in different situations;

To determine the motion of the passenger inside the vehicles; and

To state inertia in your own words.

Objectives

The property of a body that resists changes in a body’s condition of rest or of motion with constant velocity.

The tendency of an object to persist in its state of rest or in uniform motion in a straight line.

What is inertia?

Who have an idea of what is inertia?

GALILEO GALILEI

Newton’s First Law of Motion

According to Newton's first law...

An object at rest will remain at rest unless acted on by a force. An

object in motion continues in motion with the same speed and

in the same direction unless acted upon by a force. This law is often

called "the law of inertia".

What does this mean?

This means that there is a natural

tendency of objects to keep on doing

what they're doing. All objects resist changes in their state of motion.

Example:

Water

An object at rest will remain at rest.

An object in motion will remain in motion.

This law is the same reason why you should always wear your seatbelt.

The mass measures the inertia in our body.

“The more inertia a body has, the more difficult it is to start

moving. It will also be more difficult to stop the body if it is

originally in motion.”

Inertia is proportional to mass. Big masses resist changing their motion more than smaller masses.

A lot of inertia! The large train resists

changing its motion.

Very little inertia. The small baby carriage

has very little resistance to changes

in motion.

A passenger sitting in the rear of a bus claims that he was injured when the driver slammed on the brakes, causing a suitcase at the

front to come flying towards him. If you were the judge in this case, what disposition would you make

and why?

Ariel is a good racer of both the car and the single motor. He is planning to join the national

competition for each event. The problem is- both events have

the same schedule. If you were Ariel, which competition would

you choose? Justify your answer.