I think 90% of the reason to not lock this thread is for the pure comedy.
56 or 60 club face in a bunker ( various lays) - Page 6
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Here's what Greg Norman has to say about it...
Sand play is elementary physics. I was never a science whiz in school, but I learned enough to know that if you push the sand in the correct manner, it will transfer your energy and lift the ball in the way you want it to fly. It's basic earthmoving.
Let me give an example using an area where I am comfortable -- in the water. Think about splashing around in a pool. When you want to splash someone way on the other side of the pool, you whisk your palm across the top of the water with a flat, skimming motion, creating a long, low splash. When you want to douse someone right next to you, you slap downward on a sharp angle into the water, for a high, cresting splash.
Picture a golf ball riding the tops of those splashes, and you'll have a good idea of the basic forces at work in bunker play. Instead of water, your ball rides out on sand. Instead of using your hand, you use the club.
Notice there's no mention of friction.
Left? What are you talking about?
If the ball goes left, it's because you've opened your stance and are swinging a bit inward at the bottom of the club arc.
He means relative to where you're facing. Even though we all know you're aiming forward in the general sense.
The energy transferred from the clubhead, through the sand and into the ball is what moves the ball. When you are talking about several thousand grains of sand, the math might get a bit complicated, but it's the transference of the energy of all of those grains of sand against the ball that makes it move, and the sand is moved by transferring the energy from the clubhead into the sand. The direction in which the ball moves depends on the vector of the force (which is determined by angle of the clubface and the direction the club is moving) when that force is applied to the ball. Friction is not force, it is resistance to force.
The face isn't 90°. That's a myth.
And I never said the main reason is that's what gets the ball out. I said its part of why the ball goes foreward instead of go straight up which someone said. This started because of that. Yes other things play a big part but friction is like oxygen, it is apsolutely necessary and is important, not only for the obvious reasons but also to get the ball headed in the direction of the sand
Here's what you're missing...
Friction is no more important in a sand shot as it is in any other shot. That would be same as answering any golf question with "friction".
How do you hit pitch shots? Friction.
How do you hit your driver? Friction.
How do you get in your stance without infinitely sliding in the direction you moved? Friction.
How do you grip your club? Friction.
How come when you putt, the ball doesn't go 7 miles? Friction.
Friction is involved in every one of those...but do you see how it's not a reasonable answer for most of them? That's what I'm trying to explain.
Since you seriously seem like you're asking, I'll try to describe it as basic as I can...
Even if you're theoretically swinging with a 90 degree open club face, the club is not infinitely thin...if it was, then the sand (or ball) would not move forward, as the club would just glide in between all the particles. However, in the real world, the club has a volume and a mass. And when that object (club) hits the sand (assuming it hits with enough force), the sand has to go somewhere. The club displaces the sand in the direction of the movement...forward. That's what causes the sand and ball to move forward. Friction is involved, but it's also involved in every aspect of golf.
Does that make sense?
On the issue of the plane, i can't let it go, its been wracking my brain for the whole day. I am discussing it with my friend who works for NASA. So i'll have a rocket scientist opinion here soon ;)
I'm surprised that some of the more experienced Sand Trap guys are partaking in this petty quarrel. It seems to me that Nick has won this battle - not because he's right, but because he has you guys riled up and engaged in this "I'm smarter than you" back and forth...
You can take it how you want. I don't really consider petty internet arguments or debates "battles", but to each their own I suppose.
It does thank you
Let me just make sure I'm getting it though, your saying that the force of the sole on the sand is what pushes the ball foreword rather than it coming from the face? Or where does the force come from?
if you are talking about if a plane can take off of a conveyer belt the answer is no I think, unless there is an ungodly heavy wind into the nose
But on this one I'm not gonna argue my case if you think I'm wrong because apparently I really don't know anything
That's (very simplified) what starts moving the sand in the "forward" direction, yes.
As far as the plane debate, a plane doesn't move forward by its wheels. There's no engine for the wheels...there are jet engines which provide thrust. The wheels just reduce (you'll love this) friction.
Edited by Slice of Life - 9/24/13 at 10:50pm
The thing that really made me get it was that on a plane, wheels have very little effect on the movement of the airplane.
Say you tie a piece of rope to the end of each of the plane's wings, and attach the other end of the ropes to stationary towers. You can turn the treadmill up as high as you want it, those towers are keeping that plane stationary no problem. The only force they have to overcome is a small friction force between the wheels and the wheel bearings, because that's the only effect the treadmill has on the plane.
Take away the rope and the towers, and that small friction force is the only addition force necessary to overcome during liftoff.
Read Erik's post in the plane thread about the subway car with wheels welded to the roof.
What about them, and what do they have to do with whether airplanes fly, or not? Because I assure you, in spite of both, airplanes do fly.
It's all been hashed out in the thread I posted above though. Read all about it there. Really not all that complicated, it just throws some people for a bit of a loop if they don't think through what causes forward movement of an aircraft, as opposed to that of a car.
OT for this thread though.
If someone wants to continue the discussion, I'd recommend breaking out the old thread and doing so there......