“Halt or I’ll shoot!” If most of us hear these words, we’ll stop. Someone is “forcing” us to stop moving. A football player running the ball will run until someone “forces” him to stop by tackling him or running him out of bounds. A detour on our favorite route to work or school will “force” us to go a different way than we want to.
Nature is no different than us. It doesn’t want to do anything until it’s “forced” to. Force is simply making something either move when it wants to stay motionless, stop when it wants to move, or change direction from where it wants to go. It’s human nature to resist change. It’s Nature’s nature to resist change as well.
Force is such an integral part of our lives; it’s amazing anyone ever figured it out. Sir Isaac Newton is truly amazing because of the insights he gave us about the nature of motion and force. His three famous laws of motion are really about force, because force affects motion. You can’t explain motion without understanding force. You can’t explain force without understanding motion. So, let’s see…
Motion is movement from one place to another.
Speed is the rate of motion, that is, the distance covered in a certain amount of time.
Acceleration is the rate of change of speed, like speeding up or slowing down. This is where force begins to come to light. Without forcing it to change speed, an object will stay at the same speed forever, so acceleration means the object is being forced to do something.
Force can be how hard you have to try to make an object accelerate (speed up or slow down). The more mass it has, the more force it takes to make it accelerate.
Gravity is the force applied by the Earth on every object. It’s acceleration toward the center of the Earth and every object that falls has the same acceleration. Even though a bowling ball and a penny fall off the Empire State Building at the same time, the penny will do almost no damage while the bowling ball can do devastating damage because it has so much more mass than the penny. Even though the bowling ball accelerates at the same rate as the penny, it hits the ground with more force.
For those husbands out there, watching the Sunday game, realize that you are at rest and a large external force in the form of a wife with a “honey-do” list will “force” you into motion to get those projects done.