Question

How long is the barrel of the M4 compared to the M16A2?

Answer 1

The barrel of the M4 is approximately 14.5 inches long, whereas the M16A2 is approximately 20 inches long. The difference in barrel length affects the weapon's handling and ballistic characteristics. Additionally, this question addressed recoil physics in rifles, where the recoil velocity and force exerted by damping mechanisms are calculated using conservation of momentum and work-energy principles.

Step-by-step explanation:

The barrel length of the M4 is shorter compared to the M16A2. The M4 typically has a barrel length of about 14.5 inches, while the M16A2 has a barrel length of approximately 20 inches.

This difference affects the rifle's portability and range. In a professional application such as in military firearms, mechanisms exist to reduce recoil.

Let's consider the recoil of a part in the gun, often a plunger, that is directly interacting with the bullet being fired.

1. Calculating Recoil Velocity: To calculate the recoil velocity of a 1.00-kg plunger when a 0.0200-kg bullet is fired at 600 m/s, we can use conservation of momentum. The total momentum before firing is the same as after firing. Thus, 0 = (mass_bullet x velocity_bullet) + (mass_plunger x velocity_plunger), leading us to find the recoil velocity of the plunger.
2. Average Force Exerted: If the plunger is stopped over a distance of 20.0 cm, the average force exerted can be found using the work-energy principle where the work done in stopping the plunger is equal to the change in kinetic energy of the plunger. The force is then the work divided by the stopping distance.
3. Force Comparison: The force exerted on the gun if the bullet is accelerated to its velocity in 10.0 ms can be calculated using Newton's second law where force equals the rate of change of momentum. The shorter the time interval over which the bullet is accelerated, the greater the force.

Although the question deals with the differences in barrel lengths between the M4 and M16A2, the provided information is focused on the physics of recoil in firearms, specifically regarding the mechanics of a damping mechanism intended to reduce recoil forces.

By understanding the conservation of momentum and the relationship between force, distance, and time, we can calculate the recoil velocity, the average force exerted on a damping part, and compare it with the force exerted on the gun during the bullet's acceleration phase.