D

Matter

Forces can change the way objects move.

They can cause an object to change direction or stop.

TYPES OF FORCES

• Contact forces: When we apply a force to an object by making contact with it.

• Non-contact forces: when we apply a force without making contact with an object.

Friction

It is created between two surfaces when one or both objects are in movement.

It causes moving objects to slow down.

The hand push the object and the object moves.

The movement of the object creates friction between the object and the floor.

When we push an object, friction works in the opposite direction to the pushing force.

The object moves in the SAME DIRECTION as the hand, but the friction slows the object down.

NON-CONTACT FORCES

• Magnetism

• Gravity: has a greater effect on objects that have more mass and that are near. It is a pull force.

Multiple Choice

HOW MANY TYPES OF FORCES ARE THERE?

• 1

• 2

• 3

• 4

Multiple Choice

WHICH IS AN EXAMPLE OF CONTACT FORCE?

• Gravity

• Magnetism

• Friction

Multiple Choice

A non-contact force occurs when we apply a force by making contact with it.

• TRUE

• FALSE

FORCES CHANGE MATTER

We can cause changes to an object by applying a force to it.

TYPES OF FORCES

• Permament changes: when force modifies direction or speed. For example, when you play football, you can stop the ball or modify its direction. Sometimes, it change the shape of an object permanently (DEFORMATION) by applying a force. It doesn`t return to its original shape.

• Temporary changes: When a force only change shape of an object for a shor time. When the force is removed, the object returns to its original shape.

PERMANENTCHANGE

TEMPORARY CHANGE

Multiple Choice

HOW MANY TYPES OF CHANGES ARE THERE?

• 1

• 2

• 3

Multiple Choice

If a change is temporary, the shape of the object doesn't return to its original shape.

• TRUE

• FALSE

Fill in the Blanks

VELOCITY

Is the speed at which an object travels in a specific direction.

VELOCITY =SPEED IN A SPECIFIC DIRECTION

Multiple Choice

Whe can know the speed of an object if we know the direction and the time.

• TRUE

• FALSE

Multiple Choice

A... is a permanent change to the shape of an object.

• gravity

• friction

• deformation