Why people expect accuracy, when nothing is accurate?

[Guest]

Hello, my friends

I am Physics HL 

We had a discussion on accuracy

and suddenly this thought (Why people expect accuracy, when nothing is accurate???) occurred in my mind and my teacher was happy with my notion. Well what do you think about this?

Have you any such notions in your mind if so please to share it

it can also be an out of topic one

Edited January 19, 2016 by Guest

[kw0573]

Can you elaborate on your thoughts and especially your question and your viewpoint? I think if you have more dialogues on this it's good for ToK and other endeavors. So it's nice to hear about your perspectives.

Accuracy, in IB, roughly means that you are systematically getting the approximate answer. You have to appreciate that in a high school lab, only a certain degree of accuracy is attainable with the costs of equipment and number of trials time permitting. I am not a professional physicist or scientist so I can't comment on accuracy much beyond high school. IB wants in depth error analysis for a different reason, and it's up to you to figure that out. It's something more subtle than "oh if I can get this fancy equipment I will get much less error". 

I am not sure if you meant a more abstract level such like value of or in everyday uses. I guess these are more mathematical about how we can't never get to the end, and a couple dozens of decimal places can measure the radius of universe to width of an atom (so I've heard). 

[Guest]

 

 

Like there was a question on force

that is a cyclist riding the cycle at a constant velocity and we where asked to mark the vertical forces acting on the cycle so I answered gravity downwards and normal contact force upwards. Later when we checked the answer it had 3 vertical force acting upwards and 1 downwards

There wasn't much differences instead of drawing an arrow from the wheels or the pedals to the ground, I drew one big arrow downwards net force (magnitude) and the exact copy of the arrow upwards

but it was different in the marking scheme to many arrows 

that's how we discussed about accuracy 

my classmate said that ** is asking always the accurate answer my teacher said yes....

and I interrupted them saying 'but nothing is accurate' 

that's how all the latter things happened........

every thing has uncertainty.  

Edited January 20, 2016 by Guest

[kw0573]

Like there was a question on force

that is a cyclist riding the cycle at a constant velocity and we where asked to mark the vertical forces acting on the cycle so I answered gravity downwards and normal contact force upwards. Later when we checked the answer it had 3 vertical force acting upwards and 1 downwards

There wasn't much differences instead of drawing an arrow from the wheels or the pedals to the ground, I drew one big arrow downwards net force (magnitude) and the exact copy of the arrow upwards

The forces on the cycle also includes the normal force(s) down on the cycle from the rider, the normal force(s) up from Earth, and gravity down. I wouldn't call this a problem of accuracy, because the markscheme looked for one particular way of representation and you did not produce it. I think you just got it wrong. For example if you press down on the pedal really hard, the normal force increases. This information is lost if you treat cycle-cyclist interactions as a single force. For all the actions a cyclist can do, these three forces cannot be broken down to further forces, but a single net force (vectorially) in some cases loses information and makes calculations more difficult. 

 

[Guest]

 

Like there was a question on force

that is a cyclist riding the cycle at a constant velocity and we where asked to mark the vertical forces acting on the cycle so I answered gravity downwards and normal contact force upwards. Later when we checked the answer it had 3 vertical force acting upwards and 1 downwards

There wasn't much differences instead of drawing an arrow from the wheels or the pedals to the ground, I drew one big arrow downwards net force (magnitude) and the exact copy of the arrow upwards

The forces on the cycle also includes the normal force(s) down on the cycle from the rider, the normal force(s) up from Earth, and gravity down. I wouldn't call this a problem of accuracy, because the markscheme looked for one particular way of representation and you did not produce it. I think you just got it wrong. For example if you press down on the pedal really hard, the normal force increases. This information is lost if you treat cycle-cyclist interactions as a single force. For all the actions a cyclist can do, these three forces cannot be broken down to further forces, but a single net force (vectorially) in some cases loses information and makes calculations more difficult. 

 

 

ya anyways some how this chit chat about accuracy broke I don't know how, but my answer was correct because of the magnitude of the arrows.

Edited January 22, 2016 by Guest