an experiment to make a parachute

Gravitational forces

Gravitational force is a force that can act at a distance. Every planets have different gravitational forces. Gravitational forces pulls all things downwards, towards the center of the world.

Mass or weight

all objects on the have weight. If we move away from earth, the gravitational force becomes weaker. so, the weight of an object decreases. mass and weight can be measured, but the difference is that weight is a force and mass is not a force. the mass of an object is the same, even somewhere else. the weight of an object is different, even whe is somewhere else.


Frictional force


frictional force is a force that opposes motion. it is produced when two surfaces rub against each other for example: pushing a toy car, push the door.frictional force has many affects. it can:

• slow down and stop moving objects.
• prevent an object from starting to move.
• affect the movement of objects on different surfaces

Air resistance


the frictional force acting on object as they move through air or as air flows around them is called air resistance. Air resistance slows down the moving object. this experiment we do is to test the air resistance slowing down the parachute.

Water resistance


water resistance has more friction than air resistance. if we drop a chalk into a beaker fill with water, it slows down the chalk. but if we drop a chalk ito a empty beaker, it fells down faster than in water. so, water resistance has more friction than in air