A compound machine combines two or more simple machines. In essence, a machine is just a device to make work easier by allowing people to push or pull things with more force than they could on their own. Three of the simple machines are a pulley, a wheel and axle and an inclined plane. Combine these three, and you can make your own compound machine at home.
Take one of the pencils and put it through a thread spool. Tape the edges of the spool to the pencil, being careful not to tape the thread. This is the wheel and axle.
Tape the edges of the two planes together so that they form an angle. Connect the bottom of the planes with two long pieces of tape so that the structure forms a triangle. This forms the inclined plane.
Place the inclined plane on the table tape-side down. Tape one cotton swab on one side of the inclined plane, and another on the other side.
Slide the second thread spool onto the second pencil. Tape both ends of the pencil to a cotton swab. This is the pulley.
Pull some thread from the wheel and axle spool and tie it to the small object. Tape the thread in place so the small object doesn't come untied. Arrange the thread so that the small object is at the base of the wheel and axle, and the thread runs over the pulley.
Turn the wheel and axle so that the small object is lifted up the inclined plane. The pulley helps the motion along.
Refer to the resources section of this article for pictures of how to assemble this project.
Tips and warnings
- Refer to the resources section of this article for pictures of how to assemble this project.
Things you need
- Two thread spools
- Two cotton swabs
- Two pencils
- Two flat planes, such as two CD cases
- Penny, rock or other small object