Power vs speed difference?

[Michael Zhuang]

Sometimes I see rubbers that emphasize power, and some emphasize speed, but what is the difference? Isnt a ball that travels faster by definition more powerful?Â

For example, what is difference between 729 bloom power and bloom speed?Â
Â

 

[Lycanthrope]

My understanding is that Power=Speed+Spin

 

[Lazer]

There is (almost) no spin needed for power...

Cheers
L-zr

 

[UpSideDownCarl]

Which ball bites your racket harder: a ball that is fast with no spin? or a ball with a lot of spin and decent speed? Which one feels heavier when it hits your racket?

A ball that is very fast with only a little spin, slows down while still in the air. A ball with a lot of topspin will kick after the bounce and accelerate. And it will arc after the bounce and so, reach the ground while still going decently fast.

So, my understanding of power is like what Lycanthrope said: Speed + Spin = Power.

But I guess, a very fast ball with little spin may be more powerful than a slow ball with moderate to high spin depending on the speed of the fast shot.

And a moderate speed ball with an absolute ton of spin could be more powerful than a moderately fast ball with basically no spin.

 

[Lazer]

The power a ball has is exactly the power put into it when hit, no more no less.
If I do a perfect flat hit hit ALL the force goes into the ball.
If I spin the ball there is always some slippage (like a fast brush) that doesn't go anywhere....
A ball with spin also loses energy in its trajectory, actually more then a non spinning ball.

Cheers
L-zr

 

[UpSideDownCarl]

The power a ball has is exactly the power put into it when hit, no more no less.
If I do a perfect flat hit hit ALL the force goes into the ball.
If I spin the ball there is always some slippage (like a fast brush) that doesn't go anywhere....
A ball with spin also loses energy in its trajectory, actually more then a non spinning ball.

Cheers
L-zr

"A ball with spin loses energy...." Yeah, it loses energy (speed and spin). But it drops towards the ground faster which means you have less time to wait for it to lose energy. Where as a flat shot will float more. There is a reason, top level players don't usually have that much trouble with someone who hits flat.

What you say is technically correct. But in TT, spin increases accuracy and also makes the ball harder to return. So, functionally, power in TT is the combination of spin + speed. But from a physics standpoint, you are correct.

 

[Lazer]

"A ball with spin loses energy...." Yeah, it loses energy (speed and spin). But it drops towards the ground faster which means you have less time to wait for it to lose energy. Where as a flat shot will float more. There is a reason, top level players don't usually have that much trouble with someone who hits flat.

What you say is technically correct. But in TT, spin increases accuracy and also makes the ball harder to return. So, functionally, power in TT is the combination of spin + speed. But from a physics standpoint, you are correct.

If You are close to table which is more difficult a smash or a hard loop?
I have never heard of anybody waiting for the ball to loose energy. and I think it is easier to return a ball with topspin hard than one without...
Sidespin makes the trajectory difficult but I would not consider it to have more power...

 

[UpSideDownCarl]

If You are close to table which is more difficult a smash or a hard loop?
I have never heard of anybody waiting for the ball to loose energy. and I think it is easier to return a ball with topspin hard than one without...
Sidespin makes the trajectory difficult but I would not consider it to have more power...

Okay. We can agree to disagree.

 

[brokenball]

Balls and rubbers don't have power. They have energy. Power is the generating energy/time. Balls and rubbers don't generate power. People do.
https://en.wikipedia.org/wiki/Watt
Balls have translational kinetic and
https://en.wikipedia.org/wiki/Kinetic_energy
rotational kinetic energy.
https://en.wikipedia.org/wiki/Rotational_energy
They also have potential energy in the form of elevation.
The kinetic energy is necessary for estimating how far the ball will penetrate into the rubber.
Neglecting spin. (1/2*)mass*velocity^2=(1/2)*k*distance^2
Where k is the spring constant.
Basically, when the ball hits the rubber, all its kinetic energy is converted to potential energy and heat in the deformation of the sponge, ball and blade. You hand absorbs some too. How fast the paddle is depends on how much of that energy that gets transferred back to the ball as kinetic energy again.
.

 

[Lazer]

Like clock work, here we go again...

 

[brokenball]

Like clock work, here we go again...

So what is wrong with my post? I have provided links. Are you going to dispute the links?
I could/should have given a more simple but maybe less intuitive answer.
Speed is measured in distance/time
Power is measured in force*distance/time.
Using metric units
speed is m/s
power is N*m/s, that is Newton*meters/second.
The units are different?
Is that clearer?
It can't get more basic than that.
Are you going to dispute this?
Do you have something against learning the truth?

The question I have is why are people trying to answer this question when clearly they don't know and they could look it up.

 

[Lazer]

So what is wrong with my post?

Yes the ball has (or excerpts) power (when it is hit, racket to ball), this power is then transferred to energy and
when the ball is traveling through the air that energy is dissipating to the air (through power)
and when hitting the table at the other side as well as the opponents racket.

You are making a fool of Yourself by marking words that a normal person would understand.

And by the way.:
No a blade can not have speed (unless you count the swing) or control. We are talking about
how fast the ball will travel after it is hit (speed) and how easy a player can control his own shots.
Those two properties are close to the inverse of each other (more speed less control)
A normal person would understand this too.

A blade has flex and hardness and at simplest it translates to speed, control and dwell time.
To give it more characteristics would complicate things beyond practicality.

 

[brokenball]

USDC, I understand exactly what Lazer is saying.
We can't both be right.
Don't tell us both answers are equally valid.
Why do you permit this nonsense?
I am not painting Lazer into a corner. He put himself there.
I can't believe it even after I post the difference between speed and power.

OK, Lazer.
How much power does a 2.7gm TT ball have traveling at 10 m/s?
This should be interesting.

It would be so funny to hear someone say I have a 5 KW or a 1 HP pingpong ball.

 

[Lazer]

You put Yourself in a corner by being so petty...

BTW.
You said "Balls and rubbers don't have power. They have energy. "
Wrong, they don't have energy, the player put energy into them, by using power.

 

[Zwill]

I don't think a human in very good physical condition can output more than 3-400W of power in a motion that resembles a table tennis stroke. But if it makes anyone feel better the Earth moves really freaking fast so all of your table tennis balls are pretty fast already.

Sometimes I see rubbers that emphasize power, and some emphasize speed, but what is the difference? Isnt a ball that travels faster by definition more powerful?Â

For example, what is difference between 729 bloom power and bloom speed?Â
Â

I haven't tried any 729 bloom rubbers yet and not much specs are written about them. But I'm assuming the manufacturer is differentiating Speed, Spin, Power so people who have a powerplay style or spin oriented style can chose the right one. Since these are really cheap rubbers probably they are just changing the sponge type or the surface tackiness. So spin is probably more tacky, power has a dead feeling hard sponge, and speed has a bouncy sponge.
They could be also playing with the topsheet rubber's pimple geometry but I don't want to give 729 too much credit in this price segment.

They are cheap rubbers, one can experiment.

 

[brokenball]

You put Yourself in a corner by being so petty...

BTW.
You said "Balls and rubbers don't have power. They have energy. "
Wrong, they don't have energy, the player put energy into them, by using power.So how much power does the 10m.s TT ball have?

Moving TT balls have energy. Not power.
Your last statement makes no sense.
First you say they have no energy and then you say the player puts the energy in them.
Yes the player transfer energy to the ball. You got that right.
But you haven't answered my question about how much power a TT ball has traveling 10m/s
I can tell you how much kinetic energy it has.
I want you to tell me how much power it has.
Why to you guys insist on being so resistant to facts when I post links to them?

The OP wants to know the difference between speed and power. I have given two ways of looking at it.
You have provided none.

 

[Zwill]

But you haven't answered my question about how much power a TT ball has traveling 10m/s

None, it's doing no acceleration, not doing any work and it has no power.
Can we move on?

 

[Lazer]

Moving TT balls have energy. Not power.
Your last statement makes no sense.
First you say they have no energy and then you say the player puts the energy in them.
Yes the player transfer energy to the ball. You got that right.
But you haven't answered my question about how much power a TT ball has traveling 10m/s
I can tell you how much kinetic energy it has.
I want you to tell me how much power it has.
Why to you guys insist on being so resistant to facts when I post links to them?

The OP wants to know the difference between speed and power. I have given two ways of looking at it.
You have provided none.

Your statement : "Balls and rubbers don't have power. They have energy. Power is the generating energy/time. Balls and rubbers don't generate power. People do."
My statement: "Wrong, they don't have energy, the player put energy into them, by using power."

My statement to OP: "There is (almost) no spin needed for power..."
This was as much targeted to Lycanthrope as it was to OP.

No one is resisting facts You have just made up Your mind to twist every statement just so You can be right...

 

[langel]

Well, rubbers vary not only in sponge hardness, but in bubbles size and structure, springiness, top sheet elasticity, thickness and hardness, pimple size, geometry and density, etc.
There are many variants of sponge/top sheet combinations. Softer sponges with softer top sheets, or with harder top sheets, harder sponges with harder top sheets, or with softer top sheets, etc., and the performance of every variant will depend on the many properties described above.

Here is a simplified and exaggerated picture of what happens with the rubbers during a direct contact and during a tangential contact.
The exact form of the deformation in both cases, as well as the size of the contact surface will depend on the particular character of the sponge/rubber combination and all their properties, described above.

But generally, in picture 2, tangential contact, you may notice that the elastic deformation of the top sheet and the sponge, plus the character of the bubbles compression, can provide a “stronger” energy transfer to the ball. So with some rubbers one may achieve a faster ball with a tangential hit. And in simple words it would be a “great spin power rubber”, though not scientifically correct.

Of course the result will depend not only on everything mentioned, but on the blade too, as well as on all forces applied, and any graph, describing speed and spin will have different form. The differences in these graphs make people give different “names” describing the most “special” characteristics, rather than using correct, but telling nothing to the audience terminology /like COR for example/.

 

[Zwill]

Cool drawing.
Here are some high speed camera shots made by Mizuno: