Calculate Foot-Pounds of Energy

Pellet Weight (grains):
Velocity (fps):

Foot-Pounds of Energy: " . $energy_ftlbs . "

"; } // Function to calculate foot-pounds of energy function calculateEnergy($weight_grains, $velocity_fps) { // Convert grain weight to pounds $weight_lbs = $weight_grains / 7000; // Calculate energy in foot-pounds $energy_ftlbs = 0.5 * $weight_lbs * pow($velocity_fps, 2) / 32.174; return $energy_ftlbs; } ?>