PeroK's latest activity
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PeroK replied to the thread Dynamics of Circular Motion.That equation is not correct. Note that it's not necessary to find the normal force. You already know the centripetal and tangential... -
PeroK replied to the thread Dynamics of Circular Motion.I think that looking at forces adds unnecessary calculations, as you know the acceleration of the ball. There is no need to calculate...
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PeroK replied to the thread Dynamics of Circular Motion.I didn't think of doing it your way. Let me have a look at that method. The approach I took was: You have correctly determined the...
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PeroK replied to the thread B Why Does Hooke's Law Use a Negative Sign in Scalar Form?.Although there are three spatial dimensions, the use of 2D or 1D vectors for systems confined to a plane or line must be valid...
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PeroK reacted to otennert's post in the thread B Energy-time uncertainty relation for a volume and macroscopic objects? with
Informative.
I think we have covered the "time-energy uncertainty relation" a couple of times already, see e.g. here... -
PeroK reacted to Herman Trivilino's post in the thread B Why Does Hooke's Law Use a Negative Sign in Scalar Form? with Informative.
Yes. I always stressed to my students that we have to keep these three things distinct and in the fore: 1. Vectors. 2. Vector...
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PeroK replied to the thread B Why Does Hooke's Law Use a Negative Sign in Scalar Form?.There may be no best way to do it. Some students might throw a wobbler at something like ##x_x##, however rational that might be. They...
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PeroK replied to the thread I Problem in understanding instantaneous velocity.If one farmer has 20 sheep and 5 goats, and another farmer has 50 sheep and no goats, then (it seems to me) this is already a simple...
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PeroK replied to the thread I Problem in understanding instantaneous velocity.There is no problem if you understand the role of mathematics in physics. Derivatives and differential equations are fundamental. You...
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PeroK replied to the thread I Problem in understanding instantaneous velocity.This is one example where the concept of infinity can be introduced in mathematics. In this case, ##\pm \infty## become an extension of...
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PeroK replied to the thread New member! Exploring online communities.:welcome:
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PeroK reacted to dextercioby's post in the thread Suggestion Make inactive users visible by formatting username appearance with
Like.
Hi @Greg Bernhardt Could you make obvious the fact that users are inactive (last login >180 days or one year, as you wish) by making the... -
PeroK reacted to tellmesomething's post in the thread B Why Does a Spring Return to Its Original Position After Being Stretched? with
Skeptical.
Consider a spring in its natural length. I start pulling the string and the force i apply increase from 0 to 5, while this happens... -
PeroK replied to the thread B Why Does Hooke's Law Use a Negative Sign in Scalar Form?.There are many examples where we use the flexibility of our intelligence in order to used simplified or slightly inconsistent notation...
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PeroK reacted to PAllen's post in the thread I Why fixed point iteration of ##x^3 = 1-x^2## doesn't converge when ##x_0= 0## with Like.
Read what I wrote more carefully. “You won’t necessarily get convergence”. The question is when it can be guaranteed. If any iteration...