Basic Concepts in Physics

YOU ARE LEARNING:

What Is Force?

Exerting a force on an object will change its acceleration. You measure force in Newtons.

Take a good look at this image

Is this block in motion?

Which 2 things could you do to make the block move?

You can select multiple answers

The block won't start moving on its own!

To make it move, you have to exert a force on the block. This could be for example a pulling or a pushing force.

Pushing force

Is this girl in motion?

Now the girl's dad has come along and exerts a ____________ force on her.

The girl is now moving faster than she was before her dad started pushing her.

So when you exert a force on an object you can make an object go faster

In this case, the dad pushed the girl so she moved faster on her bike.

Pulling force

Is this dog in motion?

Now, the woman is exerting a _____________ force on the dog.

Will this pulling force make the dog slow down or speed up?

So when you exert a force on an object you can make an object go slower

In this case, the woman was pulling at the dog to make the dog slow down.

One more example

Is this dog in motion?

Now, the woman is exerting a _____________ force on the dog.

So when you exert a force on an object you can make an object move that wasn't moving at all before

In this case, the woman was pulling at the dog to make it get up and move.

Recap!

When you exert a force on an object you can make an object move

The little car here was stationary, but when a pulling force was exerted, it started moving.

When you exert a force on an object you can make the object move faster

This boy was moving, but when a pulling force was exerted, he had to move faster.

When you exert a force on an object you can make the object move slower

This train was moving, but when a pushing force was exerted, it slowed down.

So force can make an object move, move faster or move slower. So exerting a force changes an object's ____________.

So force changes an object's acceleration. What do you think is the unit you use for force?

True or false? There is a pulling force being exerted here.

Is it a "pulling force" or a "pushing force" that is being exerted here?

True or false? A pushing force is being exerted here.

Summary!

What is force?

When you exert a force on an object, you can make it move faster, slower, or move in the first place.

In other words

When you exert a force on an object, you change the object's acceleration (and therefore its velocity).

There are different types of forces

For example, pulling and pushing forces.

Later lessons will introduce more types of forces

For example, moment and weight are also types of forces.

The unit for force is Newtons (N)

By the way, $1 \space N$ is the force it takes to make an object with a mass of $1 \space kg$ accelerate by $1 \space m/s^2$