High impact - force - Friction

Friction

What is friction?                                                                             Friction is the resistance of motion when one object rubs against each other. When two different objects rub together, they cause friction. When an object like a ball, rolls along another object like grass, friction causes the ball to slow down and stop. When you rub your hands together, your hands create friction. Which creates heat. 

What else does friction do?                                                                                        Most things in the world would be impossible if there wasn't any friction. For example the friction between the tires of a car and the road make it possible to drive a car. Another example for friction is a roller coaster! Roller coasters depend a whole lot on friction. Friction causes the cars to slow down on the track and not go too fast. Friction causes some of the energy of motion to be converted into heat. This is why rubbing two sticks together will eventually produce a fire.

What would happen if there was no friction?                                      If there was no friction, we wouldn't be able to walk. We wouldn't be able to walk because it would be like walking on ice. If you are walking on ice, you are likely to fall over. That is because friction is reduced. It is reduced because there is less friction unlike when you walk on concrete and grass. If there was no friction, we wouldn't be able to write! We wouldn't be able to write because without friction, the pen or pencil will fall out of your hand! An eraser uses friction to get rid of pencil mistakes. Rubbing the eraser on the lead wears out the eraser due to friction, while the particles worn off gather up the pencil lead from the paper.

Friction around you...             
This is a simple friction experiment for you to try. It is called "Sticky rice friction". 
Materials - 
Dry rice
1 chopsticks
Empty 20oz bottle

Method
1. To begin, fill the bottle with rice. Try sticking the chopstick down into the bottle. When you grab the chopstick and pull up, what happens? The stick should just come right out.

2. How do you make the rice stick to the chopstick so you can just pick it up? You've got to add more friction. Here's how: Put the lid on the bottle and tap the bottom of the bottle on a hard surface. Do this a few times to compact the rice and get rid of the air pockets. Now you should have room to add a bit more rice to the bottle

3. Once you've added a bit more rice, stick the chopstick back into the bottle. This time, when you pull up on the chopstick, you should be able to pick up the whole bottle.

4. If it still doesn't stick, try tapping the bottom again. You may have to add more rice as well. Sometimes letting the rice settle for about an hour will help if it doesn't seem to be working.

How does this experiment work?