All Questions
Tagged with conservation-laws newtonian-mechanics
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Conservation of linear vs. angular momentum in two similar cases
I have a question that eludes my understanding:
Imagine we have a bullet of mass $m$ and a rigid pendulum with a bob of mass $M$ hanging from a rigid rod of negligible mass hanging from the ceiling ...
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Doubt on conservation of angular momentum for Kepler's laws
Just before proving Kepler's laws, my Professor claimed that if $\vec{F}$ is a central force with center $O$ and it is the only force acting on a point $P$, then the trajectory of $P$ is a curve plane....
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Idealized Newton's cradle
I was wondering about the conditions for an ideal newtons cradle.
Under regular circumstances, the collisions are inelastic and a newton's cradle dissipates energy in various forms like heat, friction,...
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Is there any phenomenon where opposite reaction (Newton's 3rd Law) is not fulfilled?
I'm wondering if there is any case in nature/physics where it has been observed "where there is an action, there is not necessarily an exact equal and opposite reaction".
Or is there some ...
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Could we deduce energy, momentum and angular momentum conservation laws from only Galilean relativity?
In Newtonian physics we could deduce conservation of energy, momentum and angular momentum from Newton's three laws.
But by Noether's theorem, conservation laws could be deduced from symmetries.
Could ...
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Do bodies stick together after an inelastic oblique collision?
My question is particularly about an oblique collision case. (For example a body having velocity along x axis approaching another with velocity along y axis) From what I know, in perfectly inelastic ...
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Why do basketballs with more air in them bounce more than ones with less air?
I thought it this because more air means more pressure, so there will be more pressure when the ball is deformed and it will gain more kinetic energy as it rebounds. However, some sources say that ...
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Proof for conservation of angular momentum in rotating frame of reference
imagine a simple situation such that an object is rotating on a table about a rope as seen in the below figure
now if i pull on the rope from the center , the radius of circular motion of the object ...
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Understanding kinetic energy [closed]
Let's assume I am on a boat and I throw rocks (image courtesy from Wikipedia):
From my point of view, throwing the first rock and throwing the second rock appears to make no difference. It is the ...
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Tsiolkovsky rocket equation assumptions
From what I understand, the elementary derivation of the Tsiolkovsky rocket equation makes the assumption that mass is lost as a linear function of time.
Why do we make this assumption? Does it follow ...
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Confusion in conservation of momentum [closed]
Two masses $m_1$ and $m_2$ are attached to the two ends of a rope that is sent through a pulley. Then a mass $M$ is dropped onto the mass $m_1$ from a $h$ height. So when the law of conservation of ...
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Conservation of $y$ component of momentum
Rain with mass $mr$, falling vertically downwards at speed $v$, into a truck of mass $mt$, moving on a horizontal surface at speed $u$ inital, ignoring friction and air resistance. Taking the system ...
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Rolling in opposite direction to linear motion
In this blog about a cylinder rolling up a frictionless incline, the author concludes that the cylinder will still be spinning clockwise at the top of its ascent up the hill and will then descend with ...
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Im confused on how conservation of momentum works mathematically for a problem involving a skater throwing two weights from rest [closed]
Here's the question.
A 40-kg skateboarder on a 3-kg board is training with two 5-kg weights. Beginning from rest, she throws the weights horizontally, one at a time from her board. The speed of each ...
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Momentum conservation and collisions [duplicate]
Whenever a collision happens on a rough horizontal surface, because the frictional force will be external to the system, momentum wont be conserved. However, can we consider the friction to be ...
