Gravitational Force activities (Making a Parachute)

This is how my parachute look like

Me making a parachute

Today, (Tuesday, 10/4/2012), we made a parachute for science. It is to understand more about gravitational forces around us. So, here is what we need:
1 big plastic bag (but not too big)
a bundle of string (not to thick)
scissors
a small toy

Here is how we made it:
1. Cut one side of the plastic bag into a circle.
2. Pierce small holes surrounding the circle. Do not use scissors because it will pierce big holes. Use Pen/Pencil.
3. Cut the string (approximately 50cm each) according to how many holes you pierced. (ex. if you pierced 5 holes than cut 5 strings)
4. Tie the each of the strings to each of the holes. Tie it twice so it won't untie.
5.  Attach the small toy to the bottom of the strings

And now your parachute is ready to be tested.
I tested it from the 3rd floor of my school, i tried it twice, the first time it succeed, but unfortunately at the second time, my parachute was stuck in one of the window holes. But luckily the iss (school helper) used a long stick to make the parachute not stuck. So it did. Thankyou really much.

This activity is very interesting to me because it is another way to learn about gravitational forces. And its also really fun because we can test it on our own! :D

Gravitational and Frictional Forces

GRAVITATIONAL FORCE

Gravitational Force is the force between the things and the Earth. It always pull things down to the center of the earth. The power of the gravitational force is not the same everywhere. The closer the object to the earth the greater the gravitational force. Gravitational Force is always acting around us. Some examples are when swimmer dives, man climbing the rocks and speeding up a skier.

WEIGHT AND MASS
Many people thought that Weight and Mass are the same. But actually they are different.
The similarity is that both can be measured. The difference is that Weight is a force, the gravitational force acting on an object and the weight is not the same everywhere. If Mass, it is not a force, the amount of matter in a object and the mass is same everywhere.


FRICTIONAL FORCES
Frictional force is a force that produces friction. It is produced when two surfaces rub each other. Frictional Forces can slow down and stop moving objects, prevent an object to move and affect the movement of object in different surfaces. Examples of Frictional Force is when you push a toy car, it will slow done and stops.

AIR RESISTANCE AND WATER RESISTANCE
Fictional Force also acts in air and water.
Air Resistance is a force that slows down objects in the air. It is opposing the direction of the fall of the of the object. Water Resistance that slows down objects in the water. For example if we drop a paper in a glass of water and a paper in glass without water, the piece of paper in the glass without water will fall quicker than the one with water in the glass because of the water resistance acting on it.


FRICTIONAL FORCES IN OUR DAILY LIFE
Frictional forces can he useful and can also cause problems.
It can be useful because if there is no frictional force, there will be no grip and we will not be able to hold on to anything. For example the tread patterns on the tyre help to increase the frictional force so that when the road is slippery or wet, we would not fall down.