In the baseball/pizza box thread, somebody posted a link to this, which suggests that a human punch travels at a maximum of 32 miles per hour.
It’s well known that baseball pitchers and cricket bowlers can throw/bowl at speeds of over 90 miles per hour. I don’t know how high a pitcher’s mound is, but I assume a cricket ball is about seven feet up when released. It’s going to travel about 30 feet before bouncing (a cricket pitch being 66 feet long, so the effect of gravity from the downward release doesn’t seem like it it would add much velocity - certainly not in the second or two of travel).
Having passed (barely) my secondary and collegiate physics classes, I know that an object will not accelerate unless a force continues to act on it. So, assuming the ball is traveling at 40 mph in the bowler/pitcher’s hand (I assume that the extended arm allows more velocity than a punch), and that gravity only provides slight extra impetus, where does the extra 50 mph come from?
Well, you have to take leverage into account (you are, but you’re probably still way underestimating it). Throwing a punch in the direction of the arm is going to be much slower than rotating your arm around your shoulder/elbow.
ETA: Another example - when you crack a whip, the tip even exceeds the speed of sound. There’s just much less mass in a baseball or the tip of a whip than in your entire arm.
I’d expect humeral retrotorsion would also impact the speed of the pitch. (If I’m thinking straight, the twisting of the arm would have the same effect as a helical torsion spring, imparting extra force.)
ETA: You know you’re tired when you look at something two minutes after you posted it and it doesn’t even make sense to you.
The OP can try a simple experiment himself. Hold something in your hand and throw a punch, releasing it at the end. I did this with a dum-dum sucker (it being Halloween), holding the stick between my thumb and finger, and it went poot on the floor about fifteen or so feet in front of me. Nowhere near where I could throw it with a level throw.
Any increase you’d get from the spinning you’d lose because the ball is spinning ‘backwards’ on the other side. To the best of my knowledge, the ball should start slowing down as soon as it leaves the pitcher’s hand. It’s not being provided with anymore energy at that point and is subjected to all the forces around it trying to slow it down.
As for the pitch, don’t forget to add in the speed of the pitcher’s fingers. How fast can you move your fingertips? Add that to the speed of your hand rotating around your elbow which is moving forward around your shoulder which your body is thrusting forward.
If you throw it in the forward direction with no sideways motion, and spinning causes it to move sideways, and the forward speed doesn’t drop that fast, it’ll end up moving faster, won’t it?
One possibility that occurs to me; someone who is punching is likely to (possibly unconsciously, even if they intend otherwise) be somewhat restraining the force they are using in order to prevent injury to their hand. If you are throwing a ball instead of smashing your hand into something you can go all out without worrying about breaking your fingers.
And people throwing punches don’t normally extend their arm fully the way someone pitching a ball does; that gives them less acceleration time & leverage, I’d think.
I would think that if the ball leaves the pitcher’s hand going only straight and later starts to move sideways it would HAVE to slow down. It’s going to use up some of it’s energy changing direction. Where do you think it’s picking up the extra energy that it uses when you suggest it accelerates?
As someone who spent nearly a decade doing martial arts I can add to this.
When throwing a punch, it is equally important to know when and where to stop your acceleration. It is very easy to overextend yourself and do injury to your own limb. I imagine you could throw a faster “punch” if you had no concern for the life of your joints; just throw you fist forward as hard as possible, dislocating every joint and tearing muscles along the way.
I imagine that with the velocity of a baseball pitch it is very easy to make a mistake and injure the limb in a similar manner. In fact, I’ll bet the speed of a pitch is a very careful balance between getting maximum speed from the ball and not tearing your body apart.
You’ll have to be more specific. I really can’t picture how that would work. With a football, it spins perpendicular to the direction of travel, but it doesn’t cause any acceleration, it just allows the ball to travel further because it gives the ball stability. In baseball I believe (but could very well be wrong) the ball spins, more or less, with the direction of travel, but that’s not going to cause it to accelerate. Even if it did, what about the ‘other side’ of the ball. Shouldn’t it be working against your theory since it’s traveling in the other direction?
Conservation of Energy shouldn’t allow the ball to accelerate after it’s left the pitcher’s hand.
Let’s say, viewed from the top, the ball spins clockwise (axis of spin is perpendicular to the ground) and moves upwards. Air on the left moves faster over the ball’s surface than air on the right, so pressure on the left is lower. The ball curves to the left.
Ok, I’ve found a picture http://www.science-niblets.org/sports/physics-of-a-curveball.html but they say it curves in the opposite direction.
I’ll leave baseball pitching to someone else, but I know for sure that there’s a wrist-break and finger-flick involved in delivering a cricket ball. (I also know that I don’t have the arm/hand/flick timing that allows someone to deliver at 90mph, but that’s another story.) A palm-of-the-hand delivery is one method for bowling a slower ball with unchanged arm, shoulder and body action, simply because it lacks the “flick” that gives the stock delivery its higher speed.
Even before rifling stationary firearms could shoot projectiles weighing
much more than a baseball at over 100 mph, so the speed of the emitting
body is not necessarily relevant at all.
My guess is that, as others have mentioned, the force generated by the
throwers entire body concentrates imparted energy in the thrown ball.
The force of the rear leg pushing against the ground at the moment of
release may be a particularly strong source.