Balance

A force is a push or a pull. You can feel a force when someone pushes you. You can use a force to pull a door shut. Anyone can make forces by pushing and pulling, and you don’t need to be Luke Skywalker to use a force.

In a game of tug-of-war, if the pull of your team is the same as the pull of the other team, the forces are equal. The two teams are in balance, and the rope doesn’t budge. Things are in balance when forces that are pushing or pulling them are equal.

If your tug-of-war team pulls harder than the other team, the forces are not equal. The other team falls all over the place. Unequal forces make things move and twist. A lot of things are designed to take advantage of unequal forces. Wrenches, screwdrivers, door handles, and water faucets use forces made by you to do work.

A well-balanced science diet starts with Bill Nye.

The Big Ideas

• When we push or pull on an object, we create a force.
• When forces are equal, they are in balance.
• When forces are unequal, an object moves or twists.

Did You Know That?

• N. Ravi in Sathyamangalam City, India, holds the record for balancing on one foot. He balanced for 34 hours.
• Henri Rochetain of France spent a record 185 days balanced on a tightrope. He even slept while balancing!
• Bruce Block set a record when he balanced 212 cigar boxes on his chin for 13.5 seconds in February of 1990.

Books of Science!

• “Pushing and Pulling” by Gary Gibson. Published by Aladdin Books, 1995.