THE BIGGER THEY ARE THE HARDER THEY FALL…ON YOU!

They say “The bigger they are the harder they fall”.  In earthquakes, this is true.  Why?  Because of inertia.

While the direction and force of motion in quakes is very complex, the basic effect earthquakes have on building contents can be described this way:

A passenger riding in a car experiences inertia whenever the car accelerates or decelerates rapidly.  When the drive tears out from a standstill, riders are pushed back into their seats.  If the driver slams on the brakes, then passengers are thrown forward. 

Building contents in an earthquake are like the riders in the car.  When the building moves back and forth in a quake that creates acceleration and deceleration for the items in it—a continual flooring the gas and then slamming the brakes.

How are contents affected?  Sir Isaac Newton first described the forces with this formula:

F=ma

Force is equal to the mass of an object multiplied times the acceleration of the object. 

So in a kitchen, a refrigerator and a microwave will most likely have the same acceleration in an earthquake, but because the refrigerator has more mass, it will be thrown with more force.

Don’t get the wrong impression.  BOTH items could go flying in an earthquake.  They could both get damaged and become unusable.  They could both hit you and hurt you.  It’s that a refrigerator landing on you would probably hurt quite a bit more!