Using a balance, determine the mass of the ball and basket of the ballistic pendulum. Fire the ballistic pendulum and measure the maximum height the pendulum reaches. Use the conservation of energy (initial KE + initial GPE = final KE + final GPE; KE = ½mv2; GPE = mgh) to calculate the initial speed of the pendulum after the ball has collided with the pendulum basket. Next, use the conservation of momentum (total initial p = total final p; p = mv) to determine the initial speed of the ball before it collided with the pendulum basket.