M34_Danger_Swing

Trust life and limb to something you made.

You will need:

  • Strong rope
  • Sturdy tree branch
  • Adult supervision

 

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Project Steps

WARNING

A healthy-looking branch can be rotten inside. Before you risk life and limb, inspect your hang-point carefully. Pull on it with a rope (while on solid ground). Have an adult confirm your choice.

Find a tree.

Look for a branch as big around as your waist, with lots of green leaves at the end, and no big rocks or roots directly below. Can you reach it if your rope gets stuck?

Find suitable rope. Get rope that can hold at least twice your weight, according to the “test weight” on the package. You need it to be long enough to go up to your branch and back down, plus extra for knots and loops.

Hang your rope. Hold one end and throw the other over the branch. If it’s too high, tie a rock to string and toss that over first; then use the string to pull the rope over.

Check the position.

If your rope is too far from the tree, the branch may bend or break; too close and you may bump into the trunk when you’re swinging.

Make fast, and swing! Repeat steps 3 and 4 so the rope wraps around the branch. This keeps it from slipping or sawing through the branch while you’re swinging.

Supplementary Data

A person on a swing is what physicists call a pendulum. The rate at which a pendulum swings is determined by the length of the rope from the attachment point to the swinging mass (that’s you). When we “pump” to make a swing go higher, we’re really changing the length of the pendulum. We lay back (lengthening the pendulum) as the swing goes down, and sit up (shortening it) as it goes up. It’s the fast bit at the end of the arc that makes us go a little higher. This exchange of energy is called Conservation of Angular Momentum.

Going Further

You can just hang on to the rope to swing, but your desire to swing may outlast your ability to hold the rope. Tie a stopper knot to make it easier to hold, or tie something on the end to sit on, like a board or a tire. If you’re in a park, don’t leave your swing tied to the tree. Untie knots and throw the rope back over the branch so you can pull it down.

Conclusion

Excerpted from Fifty Dangerous Things (You Should Let Your Children Do) by Gever Tulley with Julie Spiegler (fiftydangerousthings.com).