A ball with momentum 6 kg·m/s bounces off a wall and has final momentum -6 kg·m/s (opposite direction). What is the impulse delivered to the ball?
A0 kg·m/s
B6 kg·m/s
C12 kg·m/s
D−12 kg·m/s
Explanation
📌 Impulse = Δp = p_f − p_i = (−6) − (+6) = −12 kg·m/s. The magnitude is 12 kg·m/s. Distractor A: treated as if p was unchanged; B: took just p_i or p_f; D: sign confusion (though numerically same magnitude).