In Land warfare, vehicles use projectiles that fly at great speeds to hit the enemy vehicle with as much force as possible. Here are some factors that affect how the ammunition is fired.
Acceleration
Ballistics
and Trajectory
Case
Studies
Acceleration
This is a very basic topic which I'm sure you've come across in most Physics textbooks.
Acceleration is just basically the rate of change of velocity. What's velocity? Well, you can think of it as speed with a direction. Thus, acceleration has a direction, and is spread out over time.
You can see acceleration in action when your father drives at a faster speed than what he originally drove at. For example, if he originally drove at 30m/s, and he suddenly increases it to 80m/s in 5 seconds, we say that he accelerated 10m/s^2 in 1 second.
The SI unit for acceleration is 'm/s^2'. Don't forget the '^2', or you would just end up with speed!
There are 3 basic formulae relating distance, acceleration and velocity.
According to Newton's Second Law,
Force = Mass x Acceleration
After telling you these, I'm sure you'll see what importance acceleration has on warfare, especially war machines utilising projectile weapons. As it is related to distance, velocity and force, manipulating acceleration will determine how far, how fast, how accurately and how hard the projectile would strike.
As can be seen, the projectile should gain velocity very rapidly to have high acceleration and thus, be able to fly far and fast. As a result, rocket fuels are combusted in the case of missles and in the case of bullets and shells, gunpowder is used to provide the sudden gain in velocity.
Of course, on the battlefield, not everything is as perfect as it seems. There is wind velocity to compensate for, so the projectile is not blown off course or lands too far away from the target. Thus, these basic formulae are taken into consideration
Ballistics and Trajectory
Introduction
Do not be scared of these big words like trajectories and ballistics. Actually they are an integral part of warfare. If there weren't such things as ballistics and trajectories, there would not be such things as tanks and missle launchers, or the death toll would be higher, due to misfires or missiles landing in civilian towns instead to strategic targets.
But I digress.
Let's get down to serious matters. First, we'll start with trajectories, which works hand in hand with ballistics.
Trajectories
This diagram explains the terms used in the context of trajectory
There are many kinds of trajectories which a projectile can take. In fact, there are so many, it's infinite. The kind of trajectory a projectile takes depends on its acceleration, velocity and the angle from which it was fired from.
One thing to note: any trajectory taken by a projectile is a parabola. What's a parabola? It is basically a curve formed by a quadratic equation of the general form ax^2+bx+c. Thus trajectories can usually be expressed in the form of a quadratic equation.
The trajectory which would give you the longest distance covered by the projectile would be a trajectory of 45 degrees. This can be proved by calculus, which we would not delve into here. However, it is not necessarily the optimum trajectory, as some missions may require other trajectories.
If you fire a projectile at an angle lower than 45 degrees, the projectile may be pulled down by the force of gravity too soon, and it may not clear obstructions like hills and forests.
If you fire a projectile at an angle higher than 45 degrees, the projectile will fly to a very high altitude, clearing most obstacles, but it would land not far from the spot from which it was fired.
The velocity and acceleration of the projectile just determine how large the trajectory is, and how far the projectile would land.
Ballistics
Ballistics is about, well, how to fire a bullet, and more broadly, a projectile.
This is a very extensive chapter which would require tons and tons of webpages to fully explain. So, in this page, we will touch on the tip of the iceberg.
Ballistics is divided into two parts: interior ballistics and exterior ballistics.
In interior ballisitcs, ballisticians are mainly concerned with giving the projectile the highest velocity with the lowest possible maximum gas pressure. They must minimise the smoke produced, light flash which may blind the troops and erosion of the tube by repeated firings. They have to cope with many variable weather conditions such as the African summer or the Arctic winter.
To do this they must study the propellant charge, and any side effects it has on the projectile. The ballistician determines his data from his instrument, a ballistic pendulum or chronograph, and coordinates the design of the cannon, the propellant and the projectile.
In exterior ballistics, the ballistician is mainly concerned with what happens to the projectile after it leaves the gun. He analyses the trajectory, taking factors such as air resistance, centre of gravity and pressure into consideration, and comes up with the best way to hit the target. He takes the ballistic coefficient into consideration, which when varied, produces trajectories which land further.
CASE STUDIES:
