confused w/ the term "MTM"

[5263]

Originally Posted by toly

Not sure what you have in the corner there, but

I ask anyone, from Nalbanian's view,

Is his racket moving clockwise or counter clockwise?

[arche3]

Originally Posted by 5263

Not sure what you have in the corner there, but

I ask anyone, from Nalbanian's view,

Is his racket moving clockwise or counter clockwise?

Counter clockwise. Is it supposed to be clockwise?
And its a cute little picture of a clock.. lol.

[5263]

Originally Posted by arche3

Counter clockwise. Is it supposed to be clockwise?
And its a cute little picture of a clock.. lol.

I understand toly to say this will produce clockwise spin on the ball.
how?

[arche3]

Originally Posted by 5263

I understand toly to say this will produce clockwise spin on the ball.
how?

I usually have no idea what toly is getting at.

[toly]

For explanation of the ball spin direction see please picture below. Observer looks at the top of the ball.



I copied the picture from Rod Cross article, “Physics of the Tennis Kick Serve”, http://twu.tennis-warehouse.com/lear.../kickserve.php

[Cheetah]

Toly edited the picture since last night. When he first post it yesterday the ball was on the strings on lower left. It appeared the ball was being hit on the left outer side. You can see where he edited out the ball on the first racket image

[toly]

Originally Posted by Cheetah

Toly edited the picture since last night. When he first post it yesterday the ball was on the strings on lower left. It appeared the ball was being hit on the left outer side. You can see where he edited out the ball on the first racket image

Original picture you can see in http://hi-techtennis.com/.
So, my edit photoshop work is still very bad, right?

Maybe this picture is better?

[sureshs]

Originally Posted by 5263

Not sure what you have in the corner there, but

I ask anyone, from Nalbanian's view,

Is his racket moving clockwise or counter clockwise?

From Fatbandian's view, it is moving counter clockwise. At contact, it is POSSIBLE that this motion combined with the upwards motion produces clockwise rotation on the ball if it contacts the lower left of the ball.

Give a globe a spin by swiping your hands anti-clockwise wrt yourself. The globe will spin clockwise wrt you.

A simpler visualization (gleaned from helping my son in the new Principles of Engineering course they are pushing these days in high school): meshed gears spin in opposite directions.

Again, I am not sure if Fatty is contacting the ball upwards on the lower left edge, but if he is, that is what toly is saying.

[Cheetah]

Why did you edit out the ball on the strings? Weren't you trying to show how contact was made?

[sureshs]

Originally Posted by toly

For explanation of the ball spin direction see please picture below. Observer looks at the top of the ball.



I copied the picture from Rod Cross article, “Physics of the Tennis Kick Serve”, http://twu.tennis-warehouse.com/lear.../kickserve.php

I am not sure what you are saying. In a topspin kick serve, the strings and the ball move in the same general rotational direction.

[5263]

Originally Posted by sureshs

I am not sure what you are saying. In a topspin kick serve, the strings and the ball move in the same general rotational direction.

And a righty Fh will normally spin more like the lefty kick serve pic, right?
Except when he is hitting the buggy whip hooker to bring it back to the court.

No idea why toly posts a pick of kick serve spins on this Fh discussion.
Is he just trying to muddy the waters? He doesn't even attempt to tie the ideas
together, does he?

[sureshs]

Originally Posted by 5263

And a righty Fh will normally spin more like the lefty kick serve pic, right?
Except when he is hitting the buggy whip hooker to bring it back to the court.

Seems to me the direction of spin will depend on whether the inside or outside of the ball is contacted during the forehand or backhand swing.

[toly]

Does next picture clarify something?

[Cheetah]

Originally Posted by sureshs

Seems to me the direction of spin will depend on whether the inside or outside of the ball is contacted during the forehand or backhand swing.

Not entirely.

[sureshs]

Originally Posted by Cheetah

Not entirely.

And the direction of the racket swing of course ...

[sureshs]

Originally Posted by toly

Does next picture clarify something?

Has contact happened or not?

[toly]

Originally Posted by sureshs

I am not sure what you are saying. In a topspin kick serve, the strings and the ball move in the same general rotational direction.

You are absolutely right.

[toly]

Originally Posted by Cheetah

Why did you edit out the ball on the strings? Weren't you trying to show how contact was made?

I’m trying to demonstrate that we can use pronation very efficiently to create clockwise sidespin. We also can use elbow flexion. But, tip of the racquet should be directed upward.
If we want counterclockwise sidespin the racquet tip should be directed down. I believe we already discussed this matter.

[toly]

Originally Posted by sureshs

Has contact happened or not?

This is after contact.

[toly]

Originally Posted by sureshs

Seems to me the direction of spin will depend on whether the inside or outside of the ball is contacted during the forehand or backhand swing.

Direction of the sidespin is exclusively defined by direction of horizontal tangential component of the racquet velocity, because the ball is absolutely symmetrical figure about his center. Inside or outside ball have nothing to do with these types of spins.