How often do we neglect the intricacy of simple things like motion? Sure, just about everything on our planet moves to some degree, but what about objects that are given that extra little push to get going. According to the laws of motion nothing moves without some form of intervention, whether it’s in the form of a gentle breeze in the trees, or the explosive reaction that occurs inside the barrel of a gun; motion is all around!
If you have ever pondered what happens once a pitcher has rifled off a fastball, then your curiosity has led you to the complex mechanics of projectile motion. So, what differentiates simple motion from projectile motion? Actually according to physicists the ballistics of projectile motion is defined by very specific mechanical factors.
Hey, wait a minute; doesn’t ballistics pertain only to weapons like missiles and bullets? Actually the term ballistics defines the science of mechanics that deals directly with motion and the behavior of projectiles in motion.
What is a projectile?
Projectiles are commonly associated with weapons since they usually relate to bullets and other objects that can cause harm. Although the true definition states that a projectile is any object that is propelled through space by the exertion of force. Since there are a plethora of examples that could be dubbed as projectiles, it is also important to understand some of the properties that differentiate simple motion from projectile motion.
An object dropped from a great height will encounter both gravity and resistance caused external interference like air. The size and shape of the object is also an important factor that determines the amount of resistance encountered during this free fall. The most important property of a falling object is inertia, which brings us to Newton’s first law of motion.
“An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.”
This simply means if you throw something it is going to keep going until something stops it like a glove or a wall. Keeping in mind that during this action the object is still being impacted by drag and other resistance that will eventually change the intended destination.
What is motion?
In physics motion means a continuous change that affects something’s position. Many things can cause this change; however it all adds up to external force. A ball can sit still for a million years without ever being in motion, but if wind or a finger interferes it can create motion. Motion is understood with terms such as velocity, acceleration, displacement and even time. Gravity and other forces both natural and manmade all have the capability to perpetuate motion. Until an object begins to incur motion it is truly considered to be stationary or without any movement.
Projectile motion explained:
If you roll a ball across the floor you will encounter horizontal motion. If you throw a ball straight up into the air you could wind up with a concussion, but what you will have encountered is vertical motion.
Projectile motion is the combination of both horizontal and vertical motion at the same time. Since it is almost impossible to throw a ball straight up into the air you actually are creating a projectile motion model. Think of this way if the ball takes off from point A, but lands at point B, this would represent a path of projectile motion.
A good way to understand the significance of projectile motion is to watch a movie that shows a line of archers that are trying to hit a target at a fair distance. In order for the archers to hit the target they must arc the angle upwards, which as a result the arrow reaches a maximum height before descending to the intended target. The arc that is used is proportionate to projectile motion, since the projectile traversed both in a vertical and horizontal path.
Another good example of projectile motion would be the military application. Have you ever seen those old war movies where the big guns are blasting away at targets that can only be seen using binoculars? This is due to the science revolving around projectile motion. The gunnery captain uses science to ensure the intended target is hit and not his own soldiers on the field. This science of projection requires important data to accurately predict the point of impact.
The first aspect would be the Time of Ascent’ or how fast is the object dropping. Next we have the Maximum Height’, which means the highest point the object reaches before it begins descending. Last we have the Maximum Horizontal Range’, which means the distance from point A the launch point, to point B the intended target.
Interestingly in a vacuum like space there is an absence of projectile motion since any object that has force applied travels in only a vertical or horizontal direction. Only an object like another planet can affect this motion, which we can also begin to explore the complexity of orbit, but that will have to wait for another topic.
Now that you have know more about projectile motion you can finally understand how difficult it can be for a sniper to hit a target from an extreme distance, or what is involved to ensure innocent civilians are not harmed when using projectiles in warfare. Hey, it might even help your future chances of finally nailing that pin during your next game of horseshoes!