Unit 19 - Gravitational and Frictional force

Gravitational force: Gravitational force is a force that can act from a distance from an object. It is the force of attraction between things and the Earth. Gravitational force pull things downwards to the center of the Earth. Its strength is not the same everywhere. The farther the object from the center of the Earth the weaker the gravitational force. Gravitational force acting on us and all other objects all time. That way we will not float away to space.

Frictional force: Frictional force is a force that opposes motion. It is produced when two surface rub against each other. Frictional force can slow down objects, prevent an object to move and affect the movement of an object.

Air resistance: Air resistance occurs when we drop an object and te frictional force slows the speed of the fall. Example of objects using air resistance is a parachute.

We also make a parachute for our portfolio. But my parachute failed.

Air and Water

      

Living things need air and water to live. But, with so many living things on Earth, how would there be enough air and water? To make the air and water enough, there are some cycles. The water and the oxygen and corbon dioxide cycle. The water cycle: The sun cause the water in water bodies to evaporate to become clouds, when the clouds gets too heavy, it falls down as rain or snow. The carbon dioxide and oxygen cycle: The plants give us oxygen while we breathe out carbon dioxide for plants to produce more oxygen.