The classic whip-off the tablecloth trick is a must!
The classic “whip off” the tablecloth trick is a must for any aspiring science demonstrator who wants to be amazing! This experiment is guaranteed to either bring down the house or to get you into a lot of hot water. The idea is really quite simple – yank the tablecloth out from under a beautiful place setting without destroying the meal (or the place setting). It’s easy if you take a science lesson from Sir Isaac Newton.
- Flat tabletop, preferably with a straight edge
- Dinner plates, saucers, and glasses with smooth bottom surfaces (the heavier, the better)
- Spread the tablecloth out onto the tabletop with about 2 feet of the tablecloth on the table. Make sure there are no wrinkles.
- Place the cups, plates and utensils on top of the tablecloth close to the edge of the cloth (for starters). This makes for less tablecloth to have to pull out from underneath the stuff on top.
- The trick is to grab the ends of the tablecloth with both hands and quickly pull the cloth straight down and away from the table. The key is the quick, downward motion – almost like you’re whipping or yanking the cloth away. Keep saying to yourself, “Pull down… not out.” Make sure to pull perpendicular to the table and not at an inclined angle.
- The only way to make this work is to just do it! If you’re nervous, start with only a dinner plate and do it over a carpeted floor. You’ll be amazed when it works and you’ll add a saucer, then a cup and so on. Okay, stop reading and try it!
Experimentation with Mom’s best dinnerware probably isn’t a great idea. In this case, “taking it further” might get you into a world of trouble. Instead of testing out different plates, bowls, and glasses, try experimenting with different masses on the plates. Make the plate or bowl heavier by adding a piece of fruit or something with some weight. Is it easier or harder to whip off the tablecloth?
How Does It Work?
After you take your bows and graciously accept your standing ovation, be sure to thank Sir Isaac Newton for his help in making you an overnight success. Plain and simple, the Tablecloth Trick works because of inertia. Newton first described inertia as the tendency for an object at rest to remain at rest until a force acts upon the object. Inertia for an object in motion is the tendency for that object to remain in motion, unless a force acts upon the object. In terms of the Tablecloth Trick, inertia is important because, according to the law, the objects (the stuff on the table) will not move unless an outside force moves them. This is known as Newton’s First Law of Motion.
There are two different parts of this experiment to discuss – inertia and friction. Initially, all of the objects (the plate, bowl, cup, utensils) are at rest (not moving). According to Newton’s First Law, objects at rest tend to stay at rest. When you pull the cloth, friction acts on the objects in the direction of the pull for a short time. The tablecloth is slippery, so these forces are small and the cloth sneaks out from underneath the objects.
If you do it just right, everyone will be amazed. Next time your mom asks you to clear the table, do it with flair!
If you aren’t sure about ripping the tablecloth out from under Mom’s dishes, try placing a piece of paper under a heavy object on the table. The object should sit on one side of the paper and the rest of the paper should stick out over the edge of the table. Hold the edge of the paper in one hand, and with a quick downward motion (think karate chop!), use your other hand to “chop” the paper and pull it out from under the object.