All Questions
Tagged with conservation-laws forces
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Apparent violation of Newton's Third Law in relativistic force transformation
In special relativity, we know that, relativistic force is defined as F = dp/dt, where p = γmv.
For forces perpendicular to the direction of relative motion, force transforms as F' = γF.
Consider two ...
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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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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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Why does a ball bounce off the wall? [duplicate]
When we throw a ball onto a wall, the ball comes in contact with the wall. And the velocity of the ball comes from V m/s to 0m/s. According Newton’s first law, a force was acted on the ball by the ...
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What contradictions would result from a violation of Newton's third law (every action has an equal and opposite reaction)?
Let's imagine we have access to a propulsion technology which can move an object, e.g. a space vessel, in one direction without moving anything (such as reaction mass) in the opposite direction. This ...
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Does gravity actually have a ‘reaction force’? [duplicate]
By (my limited knowledge of) Einstein’s theory of General Relativity, as gravity is not a force but rather the effect of an object’s inertial path following a geodesic through curved spacetime due to ...
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Is $F= ma$ applicable in only those cases where mass of the body remains constant? [duplicate]
Is it correct to say that $F= ma$ is valid for cases where mass remains constant? Suppose a snow ball is rolling down a hill and gaining mass continously so can't we say net force on snow ball at any ...
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How does conservation of momentum apply practically?
I'm doing AP Physics mechanics and I'm learning about the conservation of momentum and the textbook describes the conditions for it's validity as the net force on the system must be 0. I understand ...
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Conservation of momentum vs newton's second law
I saw this question from a book:
An empty sled is sliding on frictionless ice when Susan drops vertically from a tree down onto the sled. When she lands, does the sled speed up, slow down, or keep the ...
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Law of inertia in rotation
Consider an object rotating about its own axis. If the law of inertia is applicable, the object should keep rotating with the same angular velocity if no external torque is provided, but how is the ...
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How can there be a change in momentum with no appearent external force?
Momentum is conserved in a system with no external force.
So then let's imagine a particle of mass m being dropped from the surface of Earth's atmosphere such that there is a significant change in G ...
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Is momentum conserved when all the surfaces are smooth?
In general sense momentum conservation is making sense to me almost everywhere but when in physics problems scenarios where all surfaces become smooth and the objects are just gliding over one another ...
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Motivation and proof of Newton's 3rd law [duplicate]
I have a doubt regarding the motivation for Newton's 3rd law. Is it based on experimental evidence from collision results (where the velocities seem to redistribute based on masses and the net ...
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Is there an explanation for action-reaction law?
If a body $A$ exerts a force over body $B$, $B$ exerts a reaction force over $A$. Is there an explanation of why this happens?
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Do Magnetic forces obey Newton's Third Law? [duplicate]
If we have two magnets and one is brought towards the other, the north of the former magnet is facing north of the latter. Now the other magnet is repelled which is obvious and Newton's third law is ...
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