| I never fail to add simple machines as a home school | | | | with the same effort. |
| curriculum topic, as simple machines are interesting as | | | | Now here's my favorite home school curriculum |
| well as intriguing. Levers and pulleys are two types of | | | | experiment! |
| simple machines that help to multiply force. They | | | | The Dowel Pulley Experiment: You will need two of |
| enable you to do more work with less force. | | | | your friends, two strong 18 inch dowels and a slippery |
| To understand what a lever is imagine a see-saw in | | | | nylon rope for this experiment. Have your friends stand |
| the park. The plank that tilts from side to side is a lever, | | | | facing each other with each friend grasping a dowel |
| and the support in the center of the plank on which the | | | | with both their hands at chest level. The dowels must |
| plank pivots is the fulcrum. To understand what a | | | | be held horizontally, at the same height from the floor |
| pulley is imagine the wheel fixed over a well with a | | | | and parallel to each other. Let the two dowels be at |
| rope over it that helps to draw water from the well. A | | | | least 2 feet apart. |
| pulley is nothing but a wheel with a groove that rotates | | | | Now tie one end of the nylon rope firmly to the dowel |
| on an axle. | | | | between the hands of one friend, seeing to it that you |
| Levers and pulleys help lift or pull heavy objects. The | | | | tie it as close to one hand as possible. Now pass the |
| trick with levers and pulleys is that the farther you are | | | | rope over the other dowel and pull it from under, |
| from the fulcrum or the axle as compared to the | | | | bringing it over the first dowel. Wind the rope around |
| heavy objects, the lesser the force you will require to | | | | both dowels in such a way that two complete loops |
| lift or pull the object. I have tons of exciting | | | | are formed crisscrossing in the form of an 'M.' Now |
| experiments based on simple machines that could | | | | hold the free end of the nylon rope tightly and ask both |
| make your home school curriculum fun and easy. | | | | your friends to pull the dowels apart while you prevent |
| With a lever you can lift a person three times your | | | | them from doing it. Can they do it? |
| weight; only you will have to move three times away | | | | Now tug at the rope and ask your friends to resist |
| from the fulcrum as compared to the person's | | | | your pull. Are the two of them strong enough to resist |
| distance from the fulcrum. For example, if you weigh | | | | your tug at the rope? |
| 100 pounds, you can lift a 300 pound person who is | | | | Next, Wind the rope around both dowels in such a |
| standing 1 meter away from the fulcrum. You just | | | | way that four complete loops are formed. Now repeat |
| have to stand 3 meters away from the fulcrum. | | | | the tug of war. You will see that more the loops the |
| Similarly, you can single-handily lift 5 people who are | | | | easier it becomes for you to defeat your friends. |
| standing 10 feet away from the pulley by standing 50 | | | | What does this tell you about pulleys? |
| feet away. Aren't you amazed at the power of levers | | | | Note that the dowels act as pulleys. The more loops |
| and pulleys? | | | | mean more pulleys. The more pulleys mean less effort |
| Before we move on to our exciting experiment you | | | | you have to put in. |
| must understand what the term 'mechanical | | | | If you enjoyed this experiment, there are many more |
| advantage' or 'leverage' means. Mechanical advantage | | | | that you could ask your teacher to add to your home |
| is the maximum load you can lift with the same effort | | | | school curriculum. Fore more great science |
| on your part. After the first experiment you will learn | | | | experiments and activities visit the free "Home school |
| that the more the levers the more load you can lift | | | | Parent's Guide to Teaching Science" at the link below. |