What does 'weight' of shot mean?

[junk_baller]

By the term 'weight' I'm NOT referring to the amount of topspin on the ball. It's just that on sites like FYB they have videos where they say that if you lean into the shot the ball comes heavier off your racket. I'm not sure what they mean by this type of 'heavy'. They say that since all of your weight is behind the shot it forces your opponent back.

I'm not sure if I'm over-simplifying but I thought that the ONLY thing that matters with regards to how fast your shot is and how much spin it has on it is the racket head acceleration, speed and swing path.

Sure, maybe if you lean into the shot you may be more likely to swing harder resulting in more racket head speed, but whether you're leaning into the ball with all your 250lbs weight or you're a 90lbs girl falling backwards as you hit it - if the racket-head acceleration and speed is the same (and the swing path is the same) - both shots are going to be equally heavy and fast?

 

[Tennis Is Magic]

By the term 'weight' I'm NOT referring to the amount of topspin on the ball. It's just that on sites like FYB they have videos where they say that if you lean into the shot the ball comes heavier off your racket. I'm not sure what they mean by this type of 'heavy'. They say that since all of your weight is behind the shot it forces your opponent back.

I'm not sure if I'm over-simplifying but I thought that the ONLY thing that matters with regards to how fast your shot is and how much spin it has on it is the racket head acceleration, speed and swing path.

Sure, maybe if you lean into the shot you may be more likely to swing harder resulting in more racket head speed, but whether you're leaning into the ball with all your 250lbs weight or you're a 90lbs girl falling backwards as you hit it - if the racket-head acceleration and speed is the same (and the swing path is the same) - both shots are going to be equally heavy and fast?

Heaviness refers to the amount of force the ball impacts upon your racquet. A heavy ball is generally hit with heavy topspin because you need to hit with a lot of force to reverse the spin of the ball, and it happens to be faster than the average groundstroke after it bounces because it slows down less than flat or underspin balls. This creates a ball that puts a lot of force on your racquet, which makes the ball feel heavier.

 

[Sreeram]

Heaviness refers to the amount of force the ball impacts upon your racquet. A heavy ball is generally hit with heavy topspin because you need to hit with a lot of force to reverse the spin of the ball, and it happens to be faster than the average groundstroke after it bounces because it slows down less than flat or underspin balls. This creates a ball that puts a lot of force on your racquet, which makes the ball feel heavier.

Perfect, bulls eye.

 

[martini1]

The reverse would be a junk ball. No spin, no pace.

If that can help u to understand what a heavy ball is...

 

[[d]ragon]

Heaviness refers to the amount of force the ball impacts upon your racquet. A heavy ball is generally hit with heavy topspin because you need to hit with a lot of force to reverse the spin of the ball, and it happens to be faster than the average groundstroke after it bounces because it slows down less than flat or underspin balls. This creates a ball that puts a lot of force on your racquet, which makes the ball feel heavier.

There's this guy I know who hits a very flat forehand with lots of pace and his shots are very very heavy

 

[Netzroller]

When you hit a tennis ball, you give the ball momentum - linear and angular momentum (pace and spin). That's it.

There are lots of people trying to find some other magical component like 'weight', but it simply doesn't exist. The term 'weight' doesn't make a lot of sense talking from a physics standpoint. A tennis ball has a certain weight, which doesn't change.

Usually one refers to heavy topspin talking about weight. Imagine two balls with the same velocity, one also having heavy topspin (angular momentum). Because you have to counteract the topspin in addition to the velocity at contact, the latter is harder to handle. If the ball had no topspin, but were heavier (more linear momentum), this would have a similar effect - tha ball being harder to handle than its velocity indicates. Thus, topspin gives you the perception that this ball is 'heavier'.

 

[Tennis Is Magic]

There's this guy I know who hits a very flat forehand with lots of pace and his shots are very very heavy

Yes, generally a heavy ball is hit with topspin, but any ball can feel heavy, as long as it putts a lot of force on your racquet, but it would have to have significantly more pace than a topspin ball. I think that's why more topspin shots are regarded as being heavy as opposed to flat shots.

 

[sureshs]

There's this guy I know who hits a very flat forehand with lots of pace and his shots are very very heavy

Yes, my experience too. Heaviness can be due to plain old pace.

 

[pyrokid]

It's just the force of the impact of the ball on the racquet. You can get enough energy to do it with just pure pace, or you could hit a lot of topspin so that the ball maintains speed more after the bounce and ends up around the same speed as the flatter shot.

 

[President]

Yes, my experience too. Heaviness can be due to plain old pace.

True, but at equal speeds a shot with more topspin will have more "heaviness" than a purely flat shot.

 

[SystemicAnomaly]

Yes, my experience too. Heaviness can be due to plain old pace.

Gotta watch out about using the word, pace. Some use it to mean the linear speed of the ball. Others use it to refer to the total (kinetic) energy or momentum of the ball -- a combination of speed and spin.

http://www.tennis-x.com/fun/tennistipsdictionary.php
.

 

[UWBTennis]

I believe that the term heavy refers to the amount of spin too. My take on what FYB is saying is that weight + speed= momentum, more momentum means a more spinny ball, therefore, a more heavy ball.

 

[SystemicAnomaly]

^ The weight or heaviness is a combination of linear momentum and angular momentum (or linear KE + angular KE).

 

[Cheetah]

When you hit a tennis ball, you give the ball momentum - linear and angular momentum (pace and spin). That's it.

There are lots of people trying to find some other magical component like 'weight', but it simply doesn't exist. The term 'weight' doesn't make a lot of sense talking from a physics standpoint. A tennis ball has a certain weight, which doesn't change..

Actually, this is not true.
weight = mass x acceleration

an accelerating ball has more weight. a 'heavy ball' will pick up speed as it bounces giving it, in fact, more weight.

 

[Larrysümmers]

FORCE=mass*accel. Wt is gravity pulling the ball down, if I remember correctly from intro to physics 4 years ago.

 

[Larrysümmers]

The change in weight is caused by the ball losing air or felt. An accelerating ball isn't actually heavier at all. Its the topspin(magnus force) that pulls the ball down into the court faster than a completly flat ball. The high level of speed and magnus force is what causes the ball to feel heavy.

 

[skiracer55]

Doesn't have to be topspin...

...you can have heavy slice, too. I'm not good at the scientific explanation, so I tend to think of it as "light" versus "heavy". You get players who actually hit with a fair amount of speed, but the ball feels light, versus players who hit with a moderate amount of speed, but the ball feels like it's going to tear your arm off. And, yep, I believe it's a combination of the speed and the rotation of the ball.

Somebody did a study a few years ago that compared Sampras' shots to those of his contemporaries. Sampras had...still has...an incredibly heavy ball, and the study basically said that Sampras' shots had a ton more rotation than anyone else's.

And we could get into a whole discussion about how to produce a heavy ball, but I think we've already covered the basics. So is a heavy ball a good thing? Yep, generally, I'd say it is. But if all a player can do is hit heavy balls, eventually, the player on the other side of the net is going to get used to it. The players who really hurt their opponents are the players who can hit heavy and light. Roger Federer probably has the most variety of any current player. So he can hit an incredibly heavy topspin backhand, but he can also alternate that with a really feathery slice backhand...and nobody likes that combination.

 

[SystemicAnomaly]

Actually, this is not true.
weight = mass x acceleration

an accelerating ball has more weight. a 'heavy ball' will pick up speed as it bounces giving it, in fact, more weight.

This is not true either.

"Weight" may have numerous meanings outside of physics. Weight, in physics, is property of an object that is related to its mass and the effect of the local gravitational field. In this context it is a force due to the acceleration of gravity on an object's mass. Weight is also often used in legal and everyday parlance in reference to its mass. "Weight" also may have different meanings in sports, statistics, printing, grammar, textile (fabrics), etc.

http://dictionary.reference.com/browse/weight

http://www.thefreedictionary.com/weight

F = ma is relevant to the weight of the ball. However, when we speak of the "weight" or "heaviness" of a shot, I do not believe that we are using the word in the same manner that the physicist does.

I may be wrong but I do not believe that an accelerating ball has more weight in physics.

Balls never pick up speed when bouncing. They always experience a reduction in speed (whether they are heavy shots or not) -- they actually lose energy in the heat of compression. Balls may spin faster after a bounce, but they will never have a linear speed that is greater than their pre-bounce speed.
.

 

[Cheetah]

This is not true either.

"Weight" may have numerous meanings outside of physics. Weight, in physics, is property of an object that is related to its mass and the effect of the local gravitational field. In this context it is a force due to the acceleration of gravity on an object's mass. Weight is also often used in legal and everyday parlance in reference to its mass. "Weight" also may have different meanings in sports, statistics, printing, grammar, textile (fabrics), etc.

http://dictionary.reference.com/browse/weight

http://www.thefreedictionary.com/weight

F = ma is relevant to the weight of the ball. However, when we speak of the "weight" or "heaviness" of a shot, I do not believe that we are using the word in the same manner that the physicist does.

I may be wrong but I do not believe that an accelerating ball has more weight in physics.

Balls never pick up speed when bouncing. They always experience a reduction in speed (whether they are heavy shots or not) -- they actually lose energy in the heat of compression. Balls may spin faster after a bounce, but they will never have a linear speed that is greater than their pre-bounce speed.
.

i'm a physicist. weight has more than one definition. one of them is mass x acceleration. if you jump on a scale it will give you a higher reading than when at rest. moving objects have more mass than objects at rest as given by E=MC2. as objects accelerate they have more mass and more force than a stationary object of the same 'weight' or slower moving object of the same weight.

there is only 1 reason a ball will feel heavy and that is physics. a heavy ball is accelerating imparting more force and mass on your racket than a ball that is moving at a slower speed. as far as the player is concerned they cannot tell the difference between a 2 ounce hitting the racket ball moving at speed x and a .5 ounce ball moving at speed 2x.

 

[Cheetah]

a ball can definitely pick up speed when bouncing if it has a lot of spin. just imagine you're holding ball and drop it. then image you can flick your wrists rly fast to spin the ball and drop it at the same speed. it's going to jump off the floor faster than if it had no spin due to the angular momentum and potential energy stored in it.

 

[Cheetah]

a couple of typos there. ges it's time for bed. and i'm probably using a loose definition of accelerating. just substitute speed for that. faster objects have more mass and more energy. spinning object has more energy = more force on the racket which feels exactly the same as has the same result as if an actual heavy ball weighing say 5-6 ounces hit ur racket. .. anyway... tired. gnite.

 

[Cheetah]

... and by pick up speed i mean bounce at a faster rate than a ball bouncing that was hit with less spin

 

[zumzool]

I believe spin has very little to do with creating a heavy ball. The secret is the mass. Heavier racquets generally hit a heavier ball because of the mass in the racquet.

 

[SystemicAnomaly]

a ball can definitely pick up speed when bouncing if it has a lot of spin...

... and by pick up speed i mean bounce at a faster rate than a ball bouncing that was hit with less spin

I was starting to question if you are really a physicist with that previous claim. The point that I was making earlier is that the post-bounce speed of the ball will never be greater than the pre-bounce speed. However, the post-bounce spin rate can be greater.

 

[SystemicAnomaly]

i'm a physicist. weight has more than one definition. one of them is mass x acceleration. if you jump on a scale it will give you a higher reading than when at rest. moving objects have more mass than objects at rest as given by E=MC2. as objects accelerate they have more mass and more force than a stationary object of the same 'weight' or slower moving object of the same weight.

there is only 1 reason a ball will feel heavy and that is physics. a heavy ball is accelerating imparting more force and mass on your racket than a ball that is moving at a slower speed. as far as the player is concerned they cannot tell the difference between a 2 ounce hitting the racket ball moving at speed x and a .5 ounce ball moving at speed 2x.

E=MC2 has not really germane here. I don't believe that you are going to detect any significant mass changes until you start to approach the speed of light. I doubt that anyone here can hit a ball that fast.

Sure physics is involved but the use of the word "weight" does not appear to be used in a simple F=ma sense of the word. In what sense is a "heavy" ball accelerating? Are you referring to trajectory effects due to its spin? Are you referring to changes in the vertical speed of the ball? The horizontal speed diminishes diminishes over time (due to air drag and the court interaction). The overall speed, likewise also diminishes prior to contact.

 

[SystemicAnomaly]

I believe spin has very little to do with creating a heavy ball. The secret is the mass. Heavier racquets generally hit a heavier ball because of the mass in the racquet.

No, this is not it.

 

[Fugazi]

Heaviness refers to the amount of force the ball impacts upon your racquet. A heavy ball is generally hit with heavy topspin because you need to hit with a lot of force to reverse the spin of the ball, and it happens to be faster than the average groundstroke after it bounces because it slows down less than flat or underspin balls. This creates a ball that puts a lot of force on your racquet, which makes the ball feel heavier.

Very good explanation of the effects of spin right there.

 

[Netzroller]

Actually, this is not true.
weight = mass x acceleration

an accelerating ball has more weight. a 'heavy ball' will pick up speed as it bounces giving it, in fact, more weight.

i'm a physicist. weight has more than one definition. one of them is mass x acceleration. if you jump on a scale it will give you a higher reading than when at rest. moving objects have more mass than objects at rest as given by E=MC2. as objects accelerate they have more mass and more force than a stationary object of the same 'weight' or slower moving object of the same weight.
there is only 1 reason a ball will feel heavy and that is physics. a heavy ball is accelerating imparting more force and mass on your racket than a ball that is moving at a slower speed. as far as the player is concerned they cannot tell the difference between a 2 ounce hitting the racket ball moving at speed x and a .5 ounce ball moving at speed 2x.

a ball can definitely pick up speed when bouncing if it has a lot of spin. just imagine you're holding ball and drop it. then image you can flick your wrists rly fast to spin the ball and drop it at the same speed. it's going to jump off the floor faster than if it had no spin due to the angular momentum and potential energy stored in it.

a couple of typos there. ges it's time for bed. and i'm probably using a loose definition of accelerating. just substitute speed for that. faster objects have more mass and more energy. spinning object has more energy = more force on the racket which feels exactly the same as has the same result as if an actual heavy ball weighing say 5-6 ounces hit ur racket. .. anyway... tired. gnite.

I don't quite get your point. You say you disagree with me, but at one point you say exactly the same thing I claimed to be true – that there is only speed and spin, no 3rd component independent of these two. That a heavy spun balls feels heavier since you have to counteract the spin in addition to the speed is just what I wrote.

On the other hand, you are wrong about a few other things. And I also happen to be a physics student myself.

-Once the ball leaves the racket, there is no possible way to influence it anymore, right? So talking about accelerating balls is misleading, they're actually decelerating due to drag.
You are absolutely wrong about topspin shots accelerating after the bounce. They might slow down less than flat shots and kick up higher but still decelerate a lot.
http://wings.avkids.com/Tennis/Project/speed-02.html

-“A player cannot feel the difference between a 2ounce ball at speed x and a .5 ounce ball at speed 2x“ is wrong. They have the same momentum, but the faster ball has a higher kinetic energy! Since momentum and energy is conserved in an elastic collsion, you get different results for the racket recoil. Just use the formula for an elastic collision, you'll see. In the same way, increasing racket weight and swing speed is not the same.
Frankly, I learned this in my 1st semester as a physics stundent, it's very hard to belive you don't know this.

http://en.wikipedia.org/wiki/Collision

-You're extremely sloppy with your physics terminology, talking about something that 'stores angular momentum and potential energy' is mixing up different concepts, saying that moving objects 'having' a force is just incorrect.
You also don't need E=mc^2 here, Newtonian Mechanics does the job. Actually, I thing you're mixing up relativistic mass and rest mass here, these are not the same! The increase of relativistic mass of moving objects only gets important when you approach the speed of light, anyways. Most tennis players don't hit that hard...

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

If the object is moving slowly, the relativistic mass is nearly equal to the rest mass and both are nearly equal to the usual Newtonian mass. If the object is moving quickly, the relativistic mass is greater than the rest mass by an amount equal to the mass associated with the kinetic energy of the object.

 

[SystemicAnomaly]

^ Yup, this is my thinking. Cheetah is either not the physicist that he/she claims to be or is just plain sloppy about explaining physics concepts. When players speak of the "weight" of a shot or a "heavy ball" they are really experiencing momentum or kinetic energy (I'm not really certain which is more relevant).

Note that the ball interaction with the ground or with racket is not an elastic collision. It is an inelastic, but not perfectly inelastic, collision. So in these interactions, momentum is conserved but kinetic energy is not.

http://en.wikipedia.org/wiki/Inelastic_collision

 

[Cheetah]

sigh.. i knew this was gona happen haha. i could have spoken in strict terms but for some reason chose not too for illustration but i have failed.

bottom line is a ball feels heavy because is has more force or energy.
a faster ball has more force than a slower ball.
a faster spinning ball with pace has more mass/energy/force than a slower ball with less spin. no ifs/and/buts about it.

you dont need a heavy racket to hit a heavy ball. there is no difference between an 80 mph ball with spin X on it hit with a heavy racket than an 80 mph ball with spin X on it hit with a light racket.

the difference between momentum and kinetic energy is that momentum has a direction associated with it.

yes weight and force are different. however to the object they have the SAME effect/results.

Another reason a fast spinning ball w/ pace on it feels heavy is because of the effect the spin has on the strings upon impact. the faster spin puts more energy into the strings/wrist/arm etc making it harder to control. That energy has to go somewhere and in this case it goes into you. The more energy coming from the ball going into the racket/body etc will require more energy to control it whether its a firmer wrist, more weight behind your shot, faster racket speed etc to overcome the incoming ball.
This extra energy required makes the ball feel heavy to the observer.

There is no 'magic' to the heavy ball. It's just physics. You can put any terminology you want on it but the only difference between heavy ball A and less heavy ball B is mass and energy.

 

[Cheetah]

I don't quite get your point. You say you disagree with me, but at one point you say exactly the same thing I claimed to be true – that there is only speed and spin, no 3rd component independent of these two. That a heavy spun balls feels heavier since you have to counteract the spin in addition to the speed is just what I wrote.

On the other hand, you are wrong about a few other things. And I also happen to be a physics student myself.

-Once the ball leaves the racket, there is no possible way to influence it anymore, right? So talking about accelerating balls is misleading, they're actually decelerating due to drag.
You are absolutely wrong about topspin shots accelerating after the bounce. They might slow down less than flat shots and kick up higher but still decelerate a lot.
http://wings.avkids.com/Tennis/Project/speed-02.html

-“A player cannot feel the difference between a 2ounce ball at speed x and a .5 ounce ball at speed 2x“ is wrong. They have the same momentum, but the faster ball has a higher kinetic energy! Since momentum and energy is conserved in an elastic collsion, you get different results for the racket recoil. Just use the formula for an elastic collision, you'll see. In the same way, increasing racket weight and swing speed is not the same.
Frankly, I learned this in my 1st semester as a physics stundent, it's very hard to belive you don't know this.

http://en.wikipedia.org/wiki/Collision

-You're extremely sloppy with your physics terminology, talking about something that 'stores angular momentum and potential energy' is mixing up different concepts, saying that moving objects 'having' a force is just incorrect.
You also don't need E=mc^2 here, Newtonian Mechanics does the job. Actually, I thing you're mixing up relativistic mass and rest mass here, these are not the same! The increase of relativistic mass of moving objects only gets important when you approach the speed of light, anyways. Most tennis players don't hit that hard...

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

I used e=mc2 for simplicity because most ppl are familiar with it. In any case e=m2 still applies. And what you are referring to is the time component becoming important as you approach the speed of light. The mass component is certainly noticeable at lower speeds.
Anyway I dont want to get into a physics debate on a tennis forum but you're welcome to join me at phyicsforums.com any time.

 

[Cheetah]

I don't quite get your point. You say you disagree with me, but at one point you say exactly the same thing I claimed to be true – that there is only speed and spin, no 3rd component independent of these two. That a heavy spun balls feels heavier since you have to counteract the spin in addition to the speed is just what I wrote.

On the other hand, you are wrong about a few other things. And I also happen to be a physics student myself.

-Once the ball leaves the racket, there is no possible way to influence it anymore, right? So talking about accelerating balls is misleading, they're actually decelerating due to drag.
You are absolutely wrong about topspin shots accelerating after the bounce. They might slow down less than flat shots and kick up higher but still decelerate a lot.
http://wings.avkids.com/Tennis/Project/speed-02.html

-“A player cannot feel the difference between a 2ounce ball at speed x and a .5 ounce ball at speed 2x“ is wrong. They have the same momentum, but the faster ball has a higher kinetic energy! Since momentum and energy is conserved in an elastic collsion, you get different results for the racket recoil. Just use the formula for an elastic collision, you'll see. In the same way, increasing racket weight and swing speed is not the same.
Frankly, I learned this in my 1st semester as a physics stundent, it's very hard to belive you don't know this.

http://en.wikipedia.org/wiki/Collision

-You're extremely sloppy with your physics terminology, talking about something that 'stores angular momentum and potential energy' is mixing up different concepts, saying that moving objects 'having' a force is just incorrect.
You also don't need E=mc^2 here, Newtonian Mechanics does the job. Actually, I thing you're mixing up relativistic mass and rest mass here, these are not the same! The increase of relativistic mass of moving objects only gets important when you approach the speed of light, anyways. Most tennis players don't hit that hard...

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

If you read my previous post last night you'd see that i did address my point on acceleration after the bounce. Specifically a heavy ball will come off the ground at a faster speed than less heavy ball. Of course it will not accelerate.

 

[Cheetah]

and yes i was sloppy in my explanations. my bad. hiking at the moment. can't reply with full sentences at the moment.

 

[skiracer55]

Once again...

...we are off into the realm of "Tennis Warehouse Forum Issue Here! Paging the Ghost of Albert Einstein...a bunch of 3.5 players want to know [What's the difference between a SW and a FW backhand? | What is a heavy ball | Why can't I serve with a SW forehand grip? | How many ballpersons, really, does it take to work a Wimbledon Men's Final Match | ...long list of other metaphysical questions about tennis]."

Despite what everybody thinks, tennis is not complicated, which doesn't mean it's easy. The court hasn't changed in forever, and regardless of the fact that the tools have changed, the game actually hasn't changed all that much. The "modern forehand" is just a SW or FW forehand...doesn't make all that much difference which. And guess what? Little Bill Johnson had a really good FW forehand, which he used to great effect against Big Bill Tilden many, many years ago. Anything you want to know about how to hit a tennis ball you can find at fuzzyyellowballs.com, which is something you couldn't do even a few years ago. So read it, know it, live it...

So we can all do what we always do, which is spend another 100 or so postings on the "Physics of Heavy Balls..or Not", and that's fine, but I'll bow out of that discussion, because even though I'm a former Smart Guy, I'm not going to pretend to be able to duke it out with somebody a lot more intelligent than I am on the subject of "What makes a tennis ball heavy...or not! Really?".

Look back at my earlier post. I submit that the question really is, "Is heavy good...or not? And if it is...is it the only thing I need...or is there something else beyond just Pure Heavy Metal that might mean something to my game? And if so, how do I get Heavy plus Something More Than Heavy sometime while we're all still young, as opposed to waiting until all the votes are in from the lates [ahem] TW Seance with the Ghost of Albert Einstein?

 

[Tennis Is Magic]

I think the confusion here is that some people understand weight to mean weight = mass x acceleration due to gravity, not acceleration in general. So people are concluding that the weight of the ball cannot change, but in reality, it does. This is why a flat or backspin ball can vary in heaviness, but topspin balls are generally heavier because the ball slows down significantly less than a ball that is flatter or has backspin. Let's assume a ball with an average flight speed from the racquet to the bounce is 85 mph, and after it bounces, has a speed of 50 mph. Now lets take a ball that has an average flight speed of 75 mph, and after it bounces, has a flight speed of 60 mph. If weight is a function of mass and acceleration, and the mass does not change, which ball is heavier?

That being said, weight = mass x acceleration due to gravity is a factor. Topspin balls have higher areas of air pressure above them, forcing the ball down, increasing the effect gravity has on them, and if weight remains a constant function of mass and acceleration due to gravity, a ball with topspin will be heavier than a ball with no spin or backspin. Thus, a topspin ball generates a greater horizontal force because the ball imparts more force on the racquet at equal speed than a flat or backspin ball, and because high amounts of air pressure above the ball amplifies the effect of gravity on it, thus adding quantifiable weight to it. When you take into account BOTH effects, you can see that a topspin ball at identical velocity generates significantly more force and has noticeably more weight.