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Ft-lbs Energy Formula:
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Foot-pound (ft-lb) is a unit of energy commonly used in ballistics and firearms to measure the kinetic energy of a projectile. It represents the amount of work required to move one pound a distance of one foot.
The calculator uses the Ft-lb energy formula:
Where:
Explanation: The formula calculates kinetic energy by taking the product of mass and velocity squared, then dividing by a conversion factor that accounts for units (grains to pounds and gravitational acceleration).
Details: Calculating ft-lb energy is crucial for understanding projectile performance, comparing ammunition effectiveness, and ensuring compliance with hunting regulations that often specify minimum energy requirements.
Tips: Enter mass in grains and velocity in feet per second. Both values must be positive numbers. The calculator will compute the energy in foot-pounds.
Q1: Why is mass measured in grains?
A: Grains are the standard unit of measurement for bullet and projectile mass in ballistics, with 7,000 grains equal to one pound.
Q2: What is a typical ft-lb energy range for hunting?
A: Minimum hunting energies vary by game: small game (200-500 ft-lb), medium game (1000-1500 ft-lb), large game (1500-2500+ ft-lb).
Q3: How does velocity affect energy more than mass?
A: Because energy is proportional to velocity squared, doubling velocity quadruples energy, while doubling mass only doubles energy.
Q4: Are there limitations to this calculation?
A: This formula calculates theoretical kinetic energy and doesn't account for factors like air resistance, bullet shape, or energy transfer efficiency.
Q5: Can this calculator be used for archery?
A: Yes, though archery typically uses different units (arrow weight in grains, velocity in fps), the same formula applies for calculating kinetic energy.