Newtonian Mechanics of Arrow Penetration
A two-part technical series explaining the fundamental physics governing arrow penetration.
Introduction
Understanding arrow penetration requires separating measurable physical principles from opinion and anecdotal experience. This two-part series examines penetration using classical Newtonian mechanics and conservation of energy, providing a laboratory-based framework for evaluating arrow and broadhead performance.
Rather than focusing on individual equipment combinations, these papers establish the underlying physics that apply to every arrow system.
Paper 1
Understanding Penetration: A Newtonian Perspective
This paper introduces the fundamental mechanics of penetration, including:
- Newton's Laws of Motion
- Kinetic Energy
- Momentum
- Work and Energy
- Resistance Forces
- Deceleration during penetration
- Why penetration depth is determined by energy lost overcoming resistance
Paper 2
Penetration Mechanics: A Force-Based Perspective
Building on the first paper, this paper develops a quantitative framework for evaluating penetration by examining:
- Average and instantaneous resistance forces
- Force versus distance relationships
- Energy transfer into the target
- Laboratory methods for measuring resistance
- Comparing broadhead performance under controlled conditions
- Why controlling target resistance is essential for meaningful testing
Why These Papers Matter
Many discussions surrounding arrow penetration focus on single variables such as arrow mass, momentum, kinetic energy, or FOC. These papers demonstrate that penetration cannot be evaluated by considering any one variable in isolation. Instead, penetration is governed by the interaction between projectile energy and the resistance presented by the target.
By providing a physics-based foundation, these papers establish the framework upon which future PNL Test Standards and laboratory testing methods are built.