inertia for grade 7

Words to remember:

• Force is simply a push or a pull.

• Iners is a Latin word meaning idle or lazy.

• Mass is the measure of the amount of matter in

an object.

• Motion is the process of moving or changing

place or position.

• Friction is an unseen force that hinders motion. It

exists when a body moves along a surface.

Sir Isaac Newton

An English

scientist born

in 1642.

Most Notable for works regarding:

• Newton came up with the theory that the center of the earth was pulling the object down.

• Newton invented a new type of math called Infinitesimal Calculus.

• Newton tried to prove his theory by creating the reflecting telescope.

INERTIA ACCELERATION INTERACTION

They describe the relationship between a body and the forces acting upon it, and its motion in

response to said forces.

Presented by:

Ms. Mikaela F. Agcaoili

Experiment 1:

1. Place a peso bill on the mouth of a glass soda bottle.

2. Stack the coins directly over the mouth of the bottle, on top of the peso bill.

3. Pinch the peso bill and swipe down at the peso bill. Be careful not to hit the quarters or the bottle.

Questions:

1. What happened to the coins after you pulled the peso bill?

2. What do you think is the reason why the coins did not move even after pulling the peso bill?

Experiment 2:

1. Place the egg on a flat surface and spin it.

2. Gently and briefly place your finger on the top center of the egg.

Questions:

1.What happened to the egg after you try to stop it from spinning?

2.What do you think is the reason why the egg kept on moving after you try to stop it?

The reason why the Coins did not move

even wen we pulled the bill

or why the egg kept on moving even after

you try to stop it,

is because of INERTIA

The result of the experiments show us that

objects tends to maintain their original state.

Because you did not push the coin, it remained

on its original position.

Because you only stopped the egg’s shell but not

it’s fluid content inside it still kept on moving.

Newton’s First Law

states:

"An object at rest tends to stay at rest and an object in motion tends

to stay in motion unless acted upon by an outside force."

Came from the Latin word “Iners”.

Inertia is the natural tendency of the object to remain at rest or, if moving, to

continue its motion

What is Inertia?

Tendency of an object to resist changes in their state of motion

It tends to stay in that position unless some force puts that object into motion

If an object is at rest…

If the object is moving…

An object in motion will remain in motion unless some external force

changes the object’s motion.

More mass an object has means more inertia the

object have.

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.

.

“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.”

SITUATIONS INVOLVING INERTIA

Chilli sauce in the bottle canbe easily poured out if thebottle is moved down fastwith a sudden stop. Thesauce inside the bottlemoves together with thebottle. When the bottlestops suddenly, the saucecontinue in its state ofmotion due to the effect ofits inertia.

The passengers were in a state of motion when the

car was moving. When the car stopped suddenly,

the inertia in the passengers made them maintain

their state of motion. Thus when the car stop, the

passengers moved forward.

Safety in a car: • (a) Safety belt secure the driver to their seats.

When the car stops suddenly, the seat belt provides the external force that prevents the driver from being thrown forward.

• (b) Headrest to prevent injuries to the neck during rear-end collisions. The inertia of the head tends to keep in its state of rest when the body is moved suddenly.

A passenger sitting in the back 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, would

you believe the passenger and why?

Answer this:

Thank you for listening.Tandaan:

Magaral ng mabuti.

• Mass as something to do with how heavy an object is.

• Weight has to do with gravitational force of the material and location.