Interesting and wrong until you mention impulse. Impulse is change in momentum, so it's not just racket speed that counts, it's weight transfer. Use a heavier blade with the same technique and racket speed, you'll get more power. Same blade, but wear a weighted wrist band, again more power. What if you wear a weight belt around your hips? Then it depends on technique. No properly timed hip turn (or weight transfer technique of your choice), no increase in power. No core tension connecting hips to shoulders to elbow, etc., extra momentum dissipates before it gets to the ball, so no increase in power. But with proper technique, weight transfer makes a big difference. That's why kids less than half your weight can hit bullets.