Have you ever wondered why bullets travel such a short distance in water, while torpedoes move at an alarming speed? Unlike air, water is a much denser medium which means it requires more energy to move through. This fact is why moving through water is much more challenging than air. In this article, we will discuss the different mechanisms responsible for the difference in the speed of torpedoes and bullets when they travel in water.
Torpedoes vs Bullets- Understand the Difference
Before we jump into the difference, let’s discuss how torpedoes and bullets work. A bullet travels through the air due to a force of hot gases produced by gunpowder. But, in the case of the torpedo, the propulsion system is different. It uses mechanical energy (provided by an engine) for movement. The blades, propellers, and turbine provide an efficient locomotion system that allows them to move in water without slowing down.
What is Drag Force?
Now let’s dive into the main reason why bullets travel such a small distance in water. The answer is ‘Drag force’. Drag force is a force that opposes motion resulting from the contact of the fluid and the surface of the object. In other words, when an object moves through a fluid, it experiences resistance that steals away its speed. This resistance arises from the fact that the fluid molecules are continually colliding with the object’s surface, causing it to slow down.
The Drag force formula is:
Fd = 0.5 * rho * V^2 * Cd * A
Where Fd is the drag force, rho is the density of the fluid, V is the bullet’s velocity, Cd is the drag coefficient, and A is the bullet’s cross-section area.
As water is denser than air, drag force for bullets moving in water is much higher, making it almost enough to stop the bullet, after travelling a short distance.
How Do Torpedoes Move In Water?
Torpedoes have a unique way of moving in the water. They move using a propeller or turbine attached to an engine that provides the mechanical energy needed to move the torpedo. Water has an excellent ability to transmit energy, which makes this possible. The engine turns the blades of the propeller or turbine, which pushes water backward, causing the torpedo to move forward.
The Importance of Shape- Hydrodynamics
Hydrodynamics is the area of physics that studies how things move in fluids, such as water. When it comes to the movement of torpedoes, the main factor that determines their speed and distance is the shape of the torpedo. The outer shell of the torpedo is designed to reduce drag force and minimize turbulence, which increases the torpedo’s speed and distance. Scientists and designers use hydrodynamic design to shape most objects that are built to move in water, for example- submarines, ships, and boats.
Difference Between Torpedoes and Missiles
Now, let’s understand if we could use torpedoes in an air medium instead of missiles. The answer is ‘No,’ and the reason is the difference in densities between air and water. As discussed earlier, it requires more energy to move through a denser medium. As air is not as dense as water, torpedoes are not designed to move efficiently through the air. Similarly, missiles are designed to move efficiently through the air and not water.
Conclusion
In conclusion, we have an understanding of why torpedoes move farther than bullets underwater. The drag force, shape, and propulsion system are some of the essential factors that influence a torpedo’s distance and speed. While bullets use gunpowder, torpedoes use mechanical energy to move, which is more advantageous to their movement in water.
Torpedoes play a crucial role in naval warfare as they can travel undetected for a more extended period until it meets its target, allowing the navy to strike without alerting the opposition.
Why Does a Torpedo Travel Farther Than a Bullet Underwater?
Have you ever wondered why bullets travel such a short distance in water, while torpedoes move at an alarming speed? Unlike air, water is a much denser medium which means it requires more energy to move through. This fact is why moving through water is much more challenging than air. In this article, we will discuss the different mechanisms responsible for the difference in the speed of torpedoes and bullets when they travel in water.
Torpedoes vs Bullets- Understand the Difference
Before we jump into the difference, let’s discuss how torpedoes and bullets work. A bullet travels through the air due to a force of hot gases produced by gunpowder. But, in the case of the torpedo, the propulsion system is different. It uses mechanical energy (provided by an engine) for movement. The blades, propellers, and turbine provide an efficient locomotion system that allows them to move in water without slowing down.
What is Drag Force?
Now let’s dive into the main reason why bullets travel such a small distance in water. The answer is ‘Drag force’. Drag force is a force that opposes motion resulting from the contact of the fluid and the surface of the object. In other words, when an object moves through a fluid, it experiences resistance that steals away its speed. This resistance arises from the fact that the fluid molecules are continually colliding with the object’s surface, causing it to slow down.
Where Fd is the drag force, rho is the density of the fluid, V is the bullet’s velocity, Cd is the drag coefficient, and A is the bullet’s cross-section area.
As water is denser than air, drag force for bullets moving in water is much higher, making it almost enough to stop the bullet, after travelling a short distance.
How Do Torpedoes Move In Water?
Torpedoes have a unique way of moving in the water. They move using a propeller or turbine attached to an engine that provides the mechanical energy needed to move the torpedo. Water has an excellent ability to transmit energy, which makes this possible. The engine turns the blades of the propeller or turbine, which pushes water backward, causing the torpedo to move forward.
The Importance of Shape- Hydrodynamics
Hydrodynamics is the area of physics that studies how things move in fluids, such as water. When it comes to the movement of torpedoes, the main factor that determines their speed and distance is the shape of the torpedo. The outer shell of the torpedo is designed to reduce drag force and minimize turbulence, which increases the torpedo’s speed and distance. Scientists and designers use hydrodynamic design to shape most objects that are built to move in water, for example- submarines, ships, and boats.
Difference Between Torpedoes and Missiles
Now, let’s understand if we could use torpedoes in an air medium instead of missiles. The answer is ‘No,’ and the reason is the difference in densities between air and water. As discussed earlier, it requires more energy to move through a denser medium. As air is not as dense as water, torpedoes are not designed to move efficiently through the air. Similarly, missiles are designed to move efficiently through the air and not water.
Conclusion
In conclusion, we have an understanding of why torpedoes move farther than bullets underwater. The drag force, shape, and propulsion system are some of the essential factors that influence a torpedo’s distance and speed. While bullets use gunpowder, torpedoes use mechanical energy to move, which is more advantageous to their movement in water.
Torpedoes play a crucial role in naval warfare as they can travel undetected for a more extended period until it meets its target, allowing the navy to strike without alerting the opposition.