UNIT 7 MATTER AND FORCES

MATTER

MATTER IS ANYTHING THAT HAS MASS AND VOLUME.

MASS IS THE AMOUNT OF MATTER THAT AN OBJECT HAS. WE MEASURE MASS IN GRAMS AND KILOS. 

VOLUME IS THE SPACE THAT MATTER OCCUPIES. WE MEASURE VOLUME IN LITRES.

AIR IS ALSO MADE OF MATTER. AIR HAS MASS AND VOLUME

THE STATES OF MATTER

MATTER EXISTS IN THREE STATES

SOLIDS HAVE THEIR OWN SHAPE.

 

LIQUIDS DO NOT HAVE THEIR OWN SHAPE. THEY TAKE THE SHAPE OF THEIR CONTAINER.

GASES DO NOT HAVE THEIR OWN SHAPE. THEY TAKE THE SHAPE OF THEIR CONTAINER.

CHANGES IN MATTER

 PHYSICAL CHANGES: CHANGES OF SHAPE OR STATE 

PHYSICAL CHANGES CAN BE REVERSIBLE O IRREVERSIBLE.

REVERSIBLE CHANGES: THE SUBSTANCE CAN CHANGE BACK TO ITS ORIGINAL FORM.

IRREVERSIBLE CHANGES: THE SUBSTANCE CANNOT CHANGE BACK TO ITS ORIGINAL FORM.

 CHEMICAL CHANGES: A NEW SUBSTANCE WITH DIFFERENT CHEMICAL PROPERTIES IS PRODUCED. 

TYPES OF CHEMICAL CHANGES:

COMBUSTION: SOME MATERIALS CAN BURN AND CHANGE INTO NEW SUBSTANCES.

OXIDATION: METALS REACT WITH OXYGEN AND WATER AND RUST IS FORMED.

PUTREFACTION: WHEN ORGANIC MATTER DECOMPOSES.

FORCES

WE USE FORCES EVERYDAY: TO OPEN AND CLOSE A BOOK, TO PICK UP AN OBJECT, ETC

THERE ARE TWO TYPES OF FORCES

NON-CONTACT FORCES (THERE IS NO CONTACT WITH THE OBJECT)

GRAVITY

MAGNETS

Érase una vez los inventores: Isaac Newton

CONTACT FORCES (THERE IS CONTACT WITH THE OBJECT)

THROW OR KICK A BALL

PUSH AND PULL AN OBJECT

PREVENT AN OBJECT FROM FALLING DOWN

FRICTION IS A CONTACT FORCE. IT EXISTS WHEN TWO OBJECTS RUB AGAINST EACH OTHER. FRICTION ACTS IN THE OPPOSITE DIRECTION TO THE DIRECTION OF MOVEMENT.

FRICTION CAN SLOW DOWN OR STOP MOVING AN OBJECT. 

A PARACHUTE USES AIR FRICTION

A BOAT USES WATER FRICTION.

BUOYANCY IS A CONTACT FORCE. IT ACTS THE OPPOSITE DIRECTION TO GRAVITY ON OBJECTS IMMERSED IN A LIQUID.

THERE ARE TWO TYPES OF EFFECTS WHEN USING A FORCE:

MOVEMENT:

FORCES CAN MAKE AND OBJECT MOVE

OR STOP IT FROM MOVING

CHANGE OF SHAPE