You know that a magnet can lift objects made of iron.
Tie a small magnet to a string. Then make a wooden frame on which you can insert two pencils. Insert cotton reels on the pencils and then pull the string, attached to the magnet over the reels. Now you can use this thing as a magnetic crane to lift small objects like paper clips, pins etc. from the ground.
Lubrication is using a lubricant such as oil to reduce the effects of friction. It is easy to see the effects of lubrication. Just pour some oil on the hinges of a heavy and hard to open door. You will see that immediately the door has become easier to open and close. If you have a bicycle and have not oiled it for a long time, do it and see with how much lesser effort you can ride it.