Register to reply 
Impulse/force in pounds for the time frame 
Share this thread: 
#253
Mar1612, 07:49 PM

P: 399

As we are debating which rep with the same weight, in the same time frame puts the most tension on the muscles, as you fail at roughly 50% faster with this % and rep speeds on the fast, that’s MORE then obvious it’s the fast rep, or do you think you fail faster on the fast because it puts less tension on the muscle ??? If so please say why. Also, you said there was only one way to sort this out, with EMG, I bought one, and it showed after three experts on EMG said RMS was about the best way to find this out, that there is more overall/total activity on the fast reps. But you still insist when a real World practical experiment has proved you wrong, but you can’t state why. You keep going on about average, when as I said it means nothings, and you also cant not tell me how you or why you work out this average, what’s average got to do with this. Wayne 


#254
Mar1612, 08:13 PM

P: 399

Fast = as much force as he can exert for 20 seconds, let’s just call that 100. Slow, = 80% of his maximum force for 20 seconds. How can 80% for the same time frame be as high as 100% ??? Same in a car going uphill and down, I hit the gas 100% say this speed = 100mph, in one hour I have travelled 100 miles, you hit the gas at 80%, = 80mph, in one hour you have travelled 80 miles. [b/]You “only” travelled 80 miles as you DID NOT hit the gas with ENOUGH force, as I hit the gas with MORE force for the same time frame,[/b] 1, EMG states fast, 2, You use more energy in the fast, 3, You do more work in the fast. 4, So that’s more power in the fast, 5, You move the weight 6 times further in the fast, 6, You fail with these variables, 50% faster in the fast = there MUST be more tension on the muscles per unit of time to make them fail faster, = more tension = there must be more total/overall force if there is more tension as on failing faster. 7, More speed, velocity and acceleration on the fast. Is that enough truth, not sure what you have ??? Wayne 


#255
Mar1612, 08:51 PM

P: 399

[QUOTE=douglis;3808610]Let's redefine the question.You asked which lifting speed has greater effect of force over time(impulse) which in Wayne's world is defined as "total/overall force". Everyone explained to you that the impulse is identical regardless the lifting speed but you deny that fact based on some "practical proofs".Let's see them once again.[/quyote] Before I answer this, you NEED to state why lift you are referring to, as the two different lifts, MUST have a different impulse. Lift 1, You lift 80% of the ground, up 1m and then down 1m all in 1 second, .5/.5 Lift 2, You start at the top, lower the weight down 1m, and then lift it back up 1m all in 1 second, .5/.5 On lift 2, on the transition from negative to positive, there will be huge force on the muscles and coming from the muscles. Also, “IS” the impulse the same on 1 rep and a 100 ??? As I don’t think you are measuring the impulse with respect to time, as if you think you are, you are then saying f=ma is wrong, as your saying you don’t need a higher force to move something further in the same time frame. Slow, Car has a weight of 400kg and an Acceleration of 30m/s force pushing the car 400 x 30 = 12000N of force for 1 second. Fast, Car has a weight of 400kg and an Acceleration of 100m/s force pushing the car 400 x 100 = 40000N of force for 1 second. Fast = 2800N more for 1 second. “NOT” sure why I am wrong there, is it the deceleration ??? Do you admit you only use 80% force for the set time ??? I try to use 100% force, 80 – 100 = 20 more force used, quite simple, I use more force, thus more tension on the muscle = you fail faster. Wayne 


#256
Mar1612, 08:58 PM

P: 399

Please, for all to answer this one.
I was just wondering and thinking, ARE you adding “all” the force, I mean with the fast there are NOT just force being exerted by the muscles, there are HUGE forces on them, for say .1 of a second x the 6 reps = high forces on the muscle for maybe .6 of a second. Have you added these in ??? I mean the peak force from the transition from negative to positive, the [b]force on the muscle, NOT given out by the muscles ??? We call them the MMMTs {Momentary Maximum Muscle Tensions} these forces “ON” the muscles can be as high as 140% Have you added these on ??? Lift 1, You lift 80% of the ground, up 1m and then down 1m all in 1 second, .5/.5 Lift 2, You start at the top, lower the weight down 1m, and then lift it back up 1m all in 1 second, .5/.5 On lift 2, on the transition from negative to positive, there will be huge force on the muscles and coming from the muscles. Wayne 


#257
Mar1612, 10:28 PM

Mentor
P: 17,293

Wayne, please focus. I am trying to help you learn some physics, that is what you came here for, right? Do you understand the forcetime diagram. Do you see how the force is not constant, but that it varies over the lift? Do you graphically see what the impulse is?



#258
Mar1612, 10:43 PM

Mentor
P: 17,293

Please get back on track, if you want to get anything out of this you need to actually challenge yourself mentally and learn a bit. Do you understand the previous graph, in particular, do you see what is meant by impulse? 


#259
Mar1712, 03:37 AM

P: 148

The least thing you should do is to try to prove with physics that those variables have the effect you claim.You obviously can't even try because you lack of even basic physics knowledge so you only have two options: 1)DaleSpam has the superhuman patience to help you learn step by step some basic physics.Shut up and read carefully what he writes. 2)A better and more time saving option.....read DaleSpam's last post and just accept it as a fact with no question asked.Especially this part: 


#260
Mar1812, 06:31 PM

P: 399

Yes, and thank you Wayne 


#261
Mar1812, 06:36 PM

Sci Advisor
Thanks
PF Gold
P: 12,161

Wayne  you really can't bring yourself to believe that you are on a hiding to nothing and that what goes on in your arms is to do with your Muscles and their nonideal behaviour. Muscles are not simple machines or springs and cannot be modeled as such. If they were, you would use no energy / force / strength / bananas if you just stood and held something stationary. You know that doesn't happen. Why keep ignoring this?



#262
Mar1812, 06:45 PM

Mentor
P: 17,293




#263
Mar1812, 07:28 PM

P: 399

Will get back to the older questions.
http://www.actabio.pwr.wroc.pl/Vol4No2/2.pdf For the evaluation of muscle activities associated with force exertion the surface electromyography method is well established. The amplitude of the EMG signal quantitatively expresses muscle activity [16], [18], [32], [40] and has been used in studies of various vocations to estimate muscle loads in tasks involving upper limbs [9], [17], [38]. As maximum force exerted by the hand depends on upper limb location, for musculoskeletal load assessment it is important to determine how the value of maximum force changes in relation to upper limb location. Although studies which considered this problem (as cited above) have been performed, taking into account variety of upper limb locations, further research is still needed for normalisation purposes. The force which the muscle exerts as well as muscle tension expressed by the amplitude of the EMG signal depend on muscle length (upper limb location) [3]. Also the study of DUQUE, MASSET and MALCHAIRE [7] confirmed that differences in EMG signal amplitude in the flexor carpi radialis muscle should occur according to wrist flexion and extension, and the study of Wright (as cited in [6]) showed that the activity of the long head of the biceps brachii depends on the arm abduction and arm rotation. Muscle activity during force exertion can be spread up between muscle activity for upper limb stabilisation in a defined upper limb location and activity connected with the external force exertion. It should be expected that not only the component of muscle activity, which is responsible for upper limb stabilisation, depends on upper limb location but muscle activity associated with force exertion is influenced by upper limb location as well. Therefore, it is also an interesting problem to see whether the component of muscle activity, which is associated with handgrip force exertion, varies according to upper limb location. This is why I bought the EMG, to show what I call the total/overall muscle force or/and strength used in a set time will be different. Let me try and prove my total/overall muscle force theory. Lift a very light weight up and down for 10 seconds, lift a very heavy weight up and down for 10 seconds, and the very heavy weight will need more total/overall force. You use more energy in the fast, So that’s more power in the fast. Determine the force we will need to figure out what the weight of the barbell is (W = mg = 91 kg x 9.81 m/s = 892 kg.m/s or 892 N). Now, if work is equal to Force x distance then, U = 892 N x 1.85 m = 1650 Nm. We can calculate that lifting a 200 lb barbell overhead a distance of 1.85 m required 1650 J of work. You will notice that the time it took to lift the barbell was not taken into account. Let us only add up the positive part of the lift. The concept of power however, takes time into consideration. If for example, it took .5 seconds to complete the lift, then the power generated is 1650 J divided .5 s = 3300 J/s. If it took 2 seconds to complete the lift, then the power generated is 1650 J divided 2 s = 825 J/s. Slow set, 825 x 6 = 4950Joules. Fast set, 3300 x 25 = 82500Joules You move the weight 6 times further in the fast, You fail with these variables, 50% faster in the fast = there MUST be more tension on the muscles per unit of time to make them fail faster, = more tension = there must be more total/overall force if there is more tension as on failing faster. It will be also energy expenditure/time, oxygen debt, ATP depletion, lactate buildup, and temperature rise, but the question is, “why” do you use more of these ??? I would think there can only be one answer, as the muscles are using more total/overall force, and having more total/overall force exerted on them, thus more tension on the muscles. Question, 1, I lift and fail at 24 seconds, I lift the weight 24 times and 48m, you lift the weight for 24 seconds, you lift the weight 4 times and 8m, if wanted you could lift the weight for 48 seconds, but you stop at 24 seconds, which muscle has worked the hardest ??? Which do I use more force. 2, I lift and fail 50% faster, at 30 seconds, I then lift up a lighter weight and lift it for another 30 seconds. which muscle has worked the hardest ??? Which do I use more force, 1 or 2 ??? Which lifters muscles work the hardest ??? More speed, velocity and acceleration on the fast. Right answered that one. Wayne 


#264
Mar1912, 07:12 AM

Mentor
P: 17,293

So, let's talk a little more about impulse and see if it has the properties that you expect for "total/overall muscle force". Impulse has the property that if you exert twice the force for the same amount of time you have doubled your impulse. So, for example, if you exert 100 lbs for 10 s and I exert 50 lbs for 10 s you have exerted twice the impulse that I have. Does this agree with your concept of "total/overall muscle force"? Impulse also has the property that if you exert the same force for twice as long you have doubled your impulse. So, for example if you exert 100 lbs for 10 s and I exert 100 lbs for 5 s you have exerted twice the impulse that I have. Does this also agree with your concept of "total/overall muscle force"? 


#265
Mar1912, 11:48 AM

P: 148

It's interesting that the TMA per second is greater for the slow puh ups(in contast of what Wayne claims).For example if you check the tables 1 and 3 for the pectoralis major: for the slow push ups the TMA is 3121.81 for 101.2 sec.(TMA/t=30.85) while for the fast push ups the TMA is 2114.22 for 84.2 sec.(TMA/t=25.11) 


#266
Mar1912, 07:24 PM

P: 399

Are you trying to be sarcastic or something ??? I mean we are on a physics forum, I have all ready proved this, ITS UP TO YOU TO “TRY” AND DISPROVE IT, the cards are in my hands, the EMG states you wrong. Don’t you understand, it’s up to you to try and prove me wrong and you right, WHAT PROOF AND EVIDENCE HAVE YOU ??? 1, EMG states fast, I have the videos to prove it. All EMGs state this; it was MORE than obvious to me and most. I mean walk up a 1 mile very steep hill with a pack on your back, then “try” and run up it as fast as you can. Which is the hardest on the muscles or/and which physiologically causes the greatest stimulus, as they are fast and slow actions causing far far far different stimulus even though they produce the same mechanical work, as computed by moving the same load through the same distance. 2, You use more energy in the fast, This has been known for a 100 years, I knew this 40 years ago. And this physics site showed and proved this to you. 3, You do more work in the fast, Work is the product of a force times the distance through which it acts, I move the weight 12m you move it 2m in the same time frame. 4, So that’s more power in the fast, Lets calculate how much power I would be used on both rep speeds. Distance weight 91 kg moved 1.85 M. Determine the force we will need to figure out what the weight of the barbell is (W = mg = 91 kg x 9.81 m/s = 892 kg.m/s or 892 N). Now, if work is equal to Force x distance then, U = 892 N x 1.85 m = 1650 Nm. We can calculate that lifting a 200 lb barbell overhead a distance of 1.85 m required 1650 J of work. You will notice that the time it took to lift the barbell was not taken into account. Let us only add up the positive part of the lift. The concept of power however, takes time into consideration. If for example, it took .5 seconds to complete the lift, then the power generated is 1650 J divided .5 s = 3300 J/s. If it took 2 seconds to complete the lift, then the power generated is 1650 J divided 2 s = 825 J/s. Slow set, 825 x 6 = 4950Joules. Fast set, 3300 x 25 = 82500Joules 5, You move the weight 6 times further in the fast, I move the weight 12m you move the weight 2m 6, You fail with these variables, 50% faster in the fast = there MUST be more tension on the muscles per unit of time to make them fail faster, = more tension = there must be more total/overall force if there is more tension as on failing faster. There is a huge study proving this, have no time to find it right now, but you have seen it. And there is my video. http://www.youtube.com/watch?v=sbRVQ...1&feature=plcp 7, More speed, velocity and acceleration on the fast. Well if you don’t understand that ??? But no one is disproving what I say, like the 1 to 7 above, just try and say prove the EMG is wrong, but that’s not possible, as it’s a test that’s been done over and over by me, and 100,00 around the World, it’s one of the first tests people do when learning EMG, it’s a standard test. Then there is you fail 50% faster, I mean that’s more obvious than 1 + 1 = 2, I mean you fail faster because the faster reps, like running to walking are far hider, they are harder because your putting more total/overall tension per unit of time on the muscles, that more tension = more total/overall force per unit of time on the muscles, or what do you think it means. Why do you think your using more energy ??? Look, what happens when you run faster and faster, you use more and more force, vertical and horizontal and a little different, but basically the same, you have to use more force to run faster, and more force to rep the weight faster. Wayne 


#267
Mar1912, 07:31 PM

P: 399

Could someone please answer this.
What forces do you think you have that can make up of balance out the higher propulsive forces of the fast in the studies ??? Let’s take the mean propulsive forces, slow 6.2mean in 10.9 seconds. Fast 45.3mean 2.8 seconds, now let’s divided the mean slow of 10.9 seconds by the fast 2.8 = 3.8, so now let’s divide the slow mean by 3.8 = 1.6. Fast mean for 2.8 seconds = 45.3. Slow mean for 2.8 seconds = 1.6. The fast has nearny 3000% more mean propulsive force as in N's in the same time frame. Please what forces have I left out that the slow has to make up or balance out these ??? http://www.jssm.org/vol7/n2/16/v7n216pdf.pdf Wayne 


#268
Mar1912, 07:34 PM

P: 399

I need to get back to your other post from a few days ago, sorry there. Wayne 


#269
Mar1912, 07:53 PM

P: 399

How do you work that out ??? What machine can lift say 80% up, and then lower it down using very little energy, and what energy is this ???
Wayne And when it lowers the weight, it will have to use energy again, as in the diesel, a little less this time, but it has to use energy/diesel to move in any direction, as its using force, and this force is putting tension on the machine. Just for now take the EMG, and the fact that you fail 50% faster. Also, what have you proved ??? I see no equations, what you did say that there is no such thing as total/overall force in physics, yet the EMG reads out a higher average reading on the faster, and the EMG work with the equations of physics, they are put in the EMG. I thought is was the physics job to do the theory, and when the practical proves this wrong, the physics needs to be looked at. Wayne 


#270
Mar1912, 07:55 PM

P: 399

Could anyone please answer this ???
I was just wondering and thinking, ARE you adding “all” the force, I mean with the fast there are NOT just force being exerted by the muscles, there are HUGE forces on them, for say .1 of a second x the 6 reps = high forces on the muscle for maybe .6 of a second. Have you added these in ??? I mean the peak force from the transition from negative to positive, the force on the muscle, NOT given out by the muscles ??? We call them the MMMTs {Momentary Maximum Muscle Tensions} these forces “ON” the muscles can be as high as 140% Have you added these on ??? Lift 1, You lift 80% of the ground, up 1m and then down 1m all in 1 second, .5/.5 Lift 2, You start at the top, lower the weight down 1m, and then lift it back up 1m all in 1 second, .5/.5 On lift 2, on the transition from negative to positive, there will be huge force on the muscles and coming from the muscles. Wayne 


Register to reply 
Related Discussions  
Most force/strength used in the same time frame  General Physics  69  
Impulse question about Force and time  Introductory Physics Homework  2  
Force vs. time graph (Impulse)  Introductory Physics Homework  16  
Impulse and ForceTime Graph  Introductory Physics Homework  2  
Velocity as a function of force/impulse/time.  Introductory Physics Homework  2 