Re: Roberts: OH mini update (p.183); Happy 200!! (p.200)

[Derwood]

I also want to address the concept of deceleration. It has been mentioned the most as the reason for why diving won't work. Where is this huge deceleration you are mentioning coming from? It isn't coming from the ground as I dive into the bag, since I will have already touched the bag if I dove correctly. Where is it coming from? An object in motion stays in motion unless acted upon. That's conservation of momentum. And if the mass stays the same, that's the same thing as conservation of velocity. You don't lose velocity magically when you stop running. In fact, if there was no air resistance and no ground, you could work up to a given speed, dive, and continue at that speed forever. Any deceleration will be caused by air resistance, and that is really, really insignificant for the duration of the dive.

 

How about Gravity? When you dive you are not traveling parallel to the ground.

Gravity doesn't affect your forward momentum. How will it stop you from reaching the bag...by pulling you down towards it?

 

the overall point is that the second you stop pumping your legs, you're slowing down. also, it's not like you would just fly through the air at a constant speed if there were no gravity to pull you down, so all this "you don't slow down when you dive" stuff is nonsense

[DenverCubs]

I also want to address the concept of deceleration. It has been mentioned the most as the reason for why diving won't work. Where is this huge deceleration you are mentioning coming from? It isn't coming from the ground as I dive into the bag, since I will have already touched the bag if I dove correctly. Where is it coming from? An object in motion stays in motion unless acted upon. That's conservation of momentum. And if the mass stays the same, that's the same thing as conservation of velocity. You don't lose velocity magically when you stop running. In fact, if there was no air resistance and no ground, you could work up to a given speed, dive, and continue at that speed forever. Any deceleration will be caused by air resistance, and that is really, really insignificant for the duration of the dive.

 

How about Gravity? When you dive you are not traveling parallel to the ground.

Gravity doesn't affect your forward momentum. How will it stop you from reaching the bag...by pulling you down towards it?

 

the overall point is that the second you stop pumping your legs, you're slowing down. also, it's not like you would just fly through the air at a constant speed if there were no gravity to pull you down, so all this "you don't slow down when you dive" stuff is nonsense

You do slow down...but not much. Especially since you're only in the air for a split second.

I think we can stop the argument if everyone agrees that diving might get you there faster, but you would never do it regularly since you could get hurt and would have to time it perfectly.

[TheGrinch]

 

... it's not like you would just fly through the air at a constant speed if there were no gravity to pull you down, so all this "you don't slow down when you dive" stuff is nonsense

Actually Derwood, without air-resistance and gravity to pull you into the ground, that is EXACTLY what would happen.

 

 

I feel like I'm taking crazy pills.

Edited February 20, 2008 by TheGrinch

[Derwood]

I feel like I'm taking crazy pills.

 

if it quacks like a duck

[Yanksfan1523]

I also want to address the concept of deceleration. It has been mentioned the most as the reason for why diving won't work. Where is this huge deceleration you are mentioning coming from? It isn't coming from the ground as I dive into the bag, since I will have already touched the bag if I dove correctly. Where is it coming from? An object in motion stays in motion unless acted upon. That's conservation of momentum. And if the mass stays the same, that's the same thing as conservation of velocity. You don't lose velocity magically when you stop running. In fact, if there was no air resistance and no ground, you could work up to a given speed, dive, and continue at that speed forever. Any deceleration will be caused by air resistance, and that is really, really insignificant for the duration of the dive.

 

How about Gravity? When you dive you are not traveling parallel to the ground.

Gravity doesn't affect your forward momentum. How will it stop you from reaching the bag...by pulling you down towards it?

 

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

[DenverCubs]

I also want to address the concept of deceleration. It has been mentioned the most as the reason for why diving won't work. Where is this huge deceleration you are mentioning coming from? It isn't coming from the ground as I dive into the bag, since I will have already touched the bag if I dove correctly. Where is it coming from? An object in motion stays in motion unless acted upon. That's conservation of momentum. And if the mass stays the same, that's the same thing as conservation of velocity. You don't lose velocity magically when you stop running. In fact, if there was no air resistance and no ground, you could work up to a given speed, dive, and continue at that speed forever. Any deceleration will be caused by air resistance, and that is really, really insignificant for the duration of the dive.

 

How about Gravity? When you dive you are not traveling parallel to the ground.

Gravity doesn't affect your forward momentum. How will it stop you from reaching the bag...by pulling you down towards it?

 

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

[TheGrinch]

I also want to address the concept of deceleration. It has been mentioned the most as the reason for why diving won't work. Where is this huge deceleration you are mentioning coming from? It isn't coming from the ground as I dive into the bag, since I will have already touched the bag if I dove correctly. Where is it coming from? An object in motion stays in motion unless acted upon. That's conservation of momentum. And if the mass stays the same, that's the same thing as conservation of velocity. You don't lose velocity magically when you stop running. In fact, if there was no air resistance and no ground, you could work up to a given speed, dive, and continue at that speed forever. Any deceleration will be caused by air resistance, and that is really, really insignificant for the duration of the dive.

 

How about Gravity? When you dive you are not traveling parallel to the ground.

Gravity doesn't affect your forward momentum. How will it stop you from reaching the bag...by pulling you down towards it?

 

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

L-O-L

[Yanksfan1523]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

[Ding Dong Johnson]

... and you feel a sudden burst

 

damn, that's been driving me crazy...

[Derwood]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

 

i think they were saying "no" to your idea that being horizontal somehow makes you more prone to gravity than being upright

[DenverCubs]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

[DenverCubs]

... and you feel a sudden burst

 

damn, that's been driving me crazy...

I always said "juicy burst"

I guess it would be sudden too though.

[Yanksfan1523]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

[DenverCubs]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

Maybe think of it like this. If you set a ball on a perfectly horizontal table, it won't roll...right? Gravity can't move an object horizontally, so how could it slow you down.

[bukie]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

 

Gravity does not affect your horizontal velocity in the slightest. Wind resistance, friction and drag do. Javelins, bullets, and other things stop because they hit something. If there is nothing horizontal in the way, it hits the ground. The ground happens to have a larger friction coefficient than the air.

[TheGrinch]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

There really isn't anything to disagree about. Imagine throwing a bounce-pass with a basketball. The ball moves toward the person intended, hits the ground, and bounces up toward the person you passed it to. The whole time, it is moving at almost the same velocity horizontally (air resistance and friction slow it a little). Vertically it accelerates downward, and bounces back up to ALMOST the height you passed it from, assuming you passed it perfectly horizontally to begin with (once again, it doesn't come all the way back up because of friction). Gravity never hinders (to any significant degree...I could get way complicated here, but I won't...I'm a geophysicist) the horizontal movement.

[Mephistopheles]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

 

No a force pulling down on an object doesn't slow movement conducted at a 90 degree angle relative to the force. So here, side ways movement is completely unaffected by gravity (ish). To be VERY technical it is, but only because of the curvature of the earth, but that's pretty much irrelevant. And no, gravity works both ways. When you're diving across. The earth is pulling you to the ground AND your body is pulling the earth up to you.

[TheGrinch]

Gravity pulls you towards the earth, not an object. Wouldn't you also increase this gravitational pull by being parallel to the ground thereby having more body area affected?

no

 

Then I will ask again. Why does a bullet stop (using the theory of only minimal wind resistence as the slowing force)? Why is a javelin not thrown more on a line?

 

Please explain how gravity does not have an effect on the slowing process.

Gravity pulls you towards the Earth. Hitting the Earth stops you, not gravity. Gravity is pulling you straight down, towards the center of the Earth. It in no way affects your momentum perpendicular to the surface (forward). Air resistance slows you down in this direction, not gravity.

 

Again, a force pulling down doesn't slow the forward progress of an item in air? Only wind resistance slows the object? I would think these two factors worked in combination to slow items. Well I studied Genetics and wasn't that great at Physics, but I will have to respectfully disagree.

 

No a force pulling down on an object doesn't slow movement conducted at a 90 degree angle relative to the force. So here, side ways movement is completely unaffected by gravity (ish). To be VERY technical it is, but only because of the curvature of the earth, but that's pretty much irrelevant. And no, gravity works both ways. When you're diving across. The earth is pulling you to the ground AND your body is pulling the earth up to you.

Once you start taking into account that the Earth is curved, then you would have to also assume that the path to first base is curved...so then breaking things into components is difficult. You would have to switch over to circular polar coordinates, and when you think about it that way, gravity STILL wouldn't hinder your speed toward the bag...or I messed something up in my head. The slight effect that gravity could have on your horizontal path is under the assumption that the Earth itself is round, but that the path you are on toward the bag isn't of the same curved shape (like in reality). Things started getting complicated because then you have to use trig for that. What's the sine of 179.99999 degrees?

 

Near surface gravity (a dense boulder 100 ft. away or a huge pit dug out of the ground) would have almost as strong an effect than relation to the Earth's center at these scales anyways.

[brinoch]

Actually, the path to first base isn't curved, though of course the Earth is.

[TheGrinch]

The slight effect that gravity could have on your horizontal path is under the assumption that the Earth itself is round, but that the path you are on toward the bag isn't of the same curved shape (like in reality).

 

Actually, the path to first base isn't curved, though of course the Earth is.

:good: