Kinematics-Projectile Motion-Projectile

A projectile refers to any object whose throwing or launching takes place into the air such that it is impacted by the force of gravity. For an object to qualify as a projectile, there must be an initial force affecting it. Some common real-life examples can be a diver who jumps from aboard, a cannonball launched from a cannon, and a baseball that gets hit by a bat. In these cases, you will notice that there has been an application of some force. Due to this application of force, the object displays a motion that is known as the projectile motion. Let us learn more about this topic to know exactly what is a projectile?

What is a projectile?

A projectile is an object upon which gravity force is the only force that impacts it. You can find numerous examples of projectiles in nature. An object that is dropped from the top of a building is a projectile. However, the air resistance impacting it, in this case, should be negligible. Similarly, an object that is thrown in a vertical upward manner is also a fitting example here. Once again, air resistance should not affect it significantly in any way.  

So, projectiles are those objects that continue in motion by their own inertia, under the influence of gravity. This happens after they are projected. By its definition, gravity is the single force that affects it after its projection. As such, the object would cease to be a projectile if another force besides gravity affects it.

Types of projectiles:

There are four main types of projectiles which are as follows:

Delivery projectiles:

These projectiles carry an explosive charge, for example, the shells. They may also carry a biological or chemical substance. They may cause a special type of explosion due to an explosive payload. 

Examples of delivery projectiles are as follows:

• Early thermal weapons
• Arrow poison

Sports projectiles:

These projectiles usually refer to balls that are used in sports. Here the most important force is the propelling force that acts on the ball. Propelling forces refer to muscle forces that affect the ball and cause it to move. The stronger the propelling force, the further the distance the ball will travel. 

Examples of sports projectiles are as follows:

• A leather ball travelling at a speed of 140 km per hour in cricket after being delivered by a bowler. 
• A football that goes into a goal after being kicked by a footballer. 

Kinetic projectiles:

These projectiles are those that do not carry an explosive charge. Moreover, they are characterised by being devoid of any kind of payload. A kinetic projectile is one whose dropping can take place from an aircraft. This is applied by replacing the explosives of a regular bomb with a non-explosive material. This provides a significant precision hit and also causes significantly less collateral damage, as such kinetic projectiles are highly advantageous.

These projectiles are also known as:

• Kinetic energy weapon
• Kinetic energy warhead
• Kinetic warhead
• Kinetic kill vehicle 
• Kinetic penetrator

Examples of kinetic projectiles are as follows:

• Rocks
• Round shots
• Arrows
• Bullets
• Israeli arrow missile

Wired projectiles:

These projectiles are those whose connection takes place to launch equipment via a cable. This is how they are launched. 

Examples of wired projectiles are as follows:

• wire-guided missile
• A taser weapon
• Whaling harpoon

Properties of Projectile Motion

The projectile motion refers to the motion of an object, whose projection takes place into the air. After the initial launching force, the object only undergoes gravity force. The path that this object follows is trajectory. While travelling through the air, a frictional force will act on the object due to air resistance. 

Every object would encounter air resistance on Earth. Due to this, the motion slows down and ultimately comes to a halt after some time. In physics calculations, air resistance is generally ignored due to the difficulty in eliminating it. 

Conclusion:

A projectile is an object that gets launched or thrown into the air such that gravity impacts it. There must be an initial force that acts on an object. Only then will it be treated as a projectile. You must understand the definition and the main characteristics of projectiles. There are four main types of projectiles: delivery projectiles, sports projectiles, kinetic projectiles, and wired projectiles. Finally, you should pay attention to the various properties of its motion.