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sophiecentaur
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Mar7-12, 06:39 AM
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Quote Quote by waynexk8 View Post
Well how as a physicist would you define/call it ???
I'd call it Impulse or Work Done or whatever else I actually meant. Your problem is that you haven't really got beyond the stage of deciding what you really want to know or what you mean. We have all told you answers that could apply for a range of things that you could mean. (Please please don't give us another story to illustrate what you mean - I think I shall run out screaming at another mention of Rep Rate)

I have said this many times, to move a car 1 mile in 30 minutes, with the force of a Man pushing, you will “have” to use a certain amount of force, right ??? As if you knew the exact amount of force, and you used less force, you would not move the car 1 mile in 30 minutes, so you must be used a certain amount of force for 30 minutes. And if you moved the car 1 mile in 45 minutes, you “would” be using less overall or total force, yes ???
You start of talking about a force then you suddenly jump to "overall or total force". That's where the nonsense creeps in. Force is Force and it means just one thing. If the man pushed the car for 30 minutes, then I am assuming this would be at a steady speed on a flat road, just against friction??? What you could say is that the WORK he did was Force times the distance the car traveled.
If he pushed with less force, then the car would not be going as fast and it would cover less distance. The WORK done would be the new force times the new distance.
You seem to have some objection to describing things that way. Why? It's the way that the rest of us talk because it fits in with the rest of Physics.
You would be doing less WORK but your description, involving the word 'force' makes no sense.
I am not being sarcastic here, but when I do ??? It means I am asking you a question if you agree of not, and it’s very hard for me if you don’t answer, so please if you agree or don’t agree, please state why.
I have done that for you.



How can we add up total or overall speed. Right, let’s take an easy one, and measure speed by every .1 of a second. The object is moving at a constant speed of 100mps, so we could say JUST for arguments sake, the total or overall speed for 10 seconds = 1000.
Here you go again with 'total speed'. What you seem to mean here is that the DISTANCE is 1000 (100m/s for 10s). Speed times time = distance, doesn't it? So "total speed = distance" for you? Not good enough. You want to join the Physics club and get answers. Club rules apply, I'm afraid and you have to use the right terms or no one will understand what you're on about.

This is like they do all over the World in powerlifting, weightlifting, bodybuilding and athletics, if they have done a training day on squats and bench press; they say they have moved a certain amount of tonnage or poundage in a day. So if they did 10 x 10 squats and 10 x 10 bench press with 200 pounds, they will say they have moved 4000 poundage in one day, and if they want to get very technical, they will work or the exact amount of time they moved this poundage, and say they moved 4000 in 200 seconds, thus producing more power and force in less time than the week before hopefully.
No - they did more WORK and possibly in less time. This means more Power. The details of what forces were involved are not included in their statement.

But speed is a different thing, F = ma. If we work out the forces at work on some objects, it will be by multiplying the weight of the object by the acceleration of the object right.
The force at work on a cart pulled by a horse, the weight of the cart is 400 and an Acceleration of 20m/s to work out the Force pushing the cart is by multiplying the weight by the acceleration, 400 x 20 = 8000N in 1 second, if an acceleration of 40m/s its 400 x 40 = 16000N in 1 second. The more seconds you push the weight, the longer in seconds you will have to use this same force, as you cannot push the same weight for 10m with just using a 1 second push of 1600N can you ??? Seems like some are forgetting to add in the force with respect to time, which equals more distance the weight moved, and longer the force is applied ???

Wayne
Speed is a different thing, is it? But Maths applies to everything. The word 'total' means adding things together, whether it's cabbages or Joules. Some things just can't be 'added together' and adding speeds-at-different-times is as much forbidden as adding forces-at-different-times. This isn't poetry or stream of consciousness - it's strict and rigorous stuff.

Sorry, the last bit just reads like ramblings. I can't see what you're getting at except to tell me a story in non-technical terms. Why does a horse and cart have to be different from a man and a car? The man and car scenario says it all.

You are getting some damned good value out of all this you know.