Recent content by vxr

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    Mechanical vibrations: colliding blocks

    I saw this general formula: ##w_{0} = \sqrt{\frac{k}{m}}## In my case both masses after collision create connected system, so ##w_{0} = \sqrt{\frac{k}{m+M}}## Plugging it into ##\omega = \sqrt{\omega_{0}^2 - \beta^2}## gives : ##\omega = \sqrt{\frac{k}{m+M} - \beta^2} = \sqrt{80 - 21^2} <...
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    Man on ladder: jump off instantly vs last moment?

    Without doing any proofs, it is better to jump off last moment, right?
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    Man on ladder: jump off instantly vs last moment?

    So there are two cases: a). free fall (straight forward for me) b). ladder rotating and jumping off in last moment (I am interested in trying to understand this case) I believe I should take into account momentum at the time the man hits the ground in both cases? The smaller, the better. Or...
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    How can I calculate the acceleration of a baseball thrown by a pitcher?

    Still quite struggling with that one. Did I solve it correctly? Assume that ##s = 2.5m## ##v_{f}^2 = v_{0}^2 + 2as## ##a = \frac{v_{f}^2 - v_{0}^2}{2s}## ##a = \frac{16.6^2 - 0^2}{2*2.5}## ##a =~ 55 \frac{m}{s^2}## This is correct, right? Or.. Anyway, if that's correct then I suppose...
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    Other How to solve physics tasks to score highest?

    Hello. I am first year student, taking introductory physics course and next week I have a whole-semester exam. (kinematics, dynamics, rigid body, termodynamics, mechanical waves - that kind of basic stuff). I don't have a chance to directly ask my teacher following questions, so I figured who...
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    Connected system of a bullet and a block

    Well, if momentum is conserved, then I assume: Bullet's momentum: ##p_{1} = mv_{0}## Resting block's momentum: ##p_{2} = 0## Connected system's initial momentum: ##p = p_{1} + p_{2}## ##(m+M)v = mv_{0}## ##v = \frac{mv_{0}}{m+M}## But what I need to find is ##x## and ##t##. So if I...
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    Connected system of a bullet and a block

    Momentum of the system?
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    Connected system of a bullet and a block

    No idea. I have just assumed that it indeed does apply here. Can I get any advice how should I find the ##x##?
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    Connected system of a bullet and a block

    This is task from my textbook and it does not provide us with an answer. So I cannot verify if I did mistake. Can someone double check, please? My solution: ##E_{k_{0}} = \frac{(m+M)v_{0}^2}{2} \quad \land \quad U = \frac{kx^2}{2}## ##E_{k_{0}} = U## ##\Longrightarrow (m+M)v_{0}^2 = kx^2##...
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    Mechanical vibrations: floating apple

    Can someone double check my calculations? I will skip ##\theta## shift angle in all calculations for simplicity. ##x(t) = Acos(\omega t) \quad \land \quad \omega = \frac{2\pi}{T} \quad \land \quad A = \frac{1}{50}m = h## 1.1: ##x(\frac{1}{4}T)## = ? ##x(\frac{1}{4}T) = Acos(\frac{2\pi}{T}...
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    Mechanical vibrations: maximum velocity

    So I am almost sure I know how to solve this, just curious about the maximum velocity. Anyway, if you could double check my calculations, here it is. ##T = \frac{t}{n} = \frac{10s}{15} = \frac{2}{3}s## ##\omega = \frac{2\pi}{T} = 2\pi \frac{3}{2} = 3\pi## a). position at ##t = 0.8s##...
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    Studying materials for basics physics: exercises, not theory

    I have heard somewhere that someone who is studying basics of physics should pay a lot of attention and should spend a lot of time learning classical mechanics (kinematics, dynamics I believe), before proceeding further? By doing that it should be easier to grasp further chapters of physics. Is...
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    Studying materials for basics physics: exercises, not theory

    Good point. It is both. We had in total about 20 hours of lectures of pure theory. Problem is I am not from an english-speaking country, and our studies are taught in english. Even though I believe the teacher who held the lectures is a person of great mind, cited often around the world and...
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    Why a car decelerates after releasing the gas pedal?

    After the foot is released from the gas pedal, the car will naturally start decelerating. From my understanding two things are causing this: air resistance and kinetic friction. From my understanding also, in a vacuum and in a place where gravity is relatively small, the car would not...
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