# Tagged Questions

In introductory mechanics, the momentum of a particle is its mass times its velocity. In electrodynamics, the momentum of a field is proportional to the cross-product of the electric field with the magnetic field. In special relativity, momentum is generalized to four-momentum.

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### Impulse and momentum on a system of three particles (equilateral triangle)

I found this exercise on a textbook which provided solely the description of what is happening and the answers with little explanation. The solution being provided, I am mostly interested in ...
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### Why is a network pattern (weaving pattern) stronger than a whole solid surface of the same material

For example badminton racquets and huts.
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### Is the Impulse-Momentum Theorem True? [closed]

This is just a general question I want to throw out there, and see arguments from both sides... Is Impulse-Momentum Theorem True? Well in my opinion I would say yes because it is a derived equation: ...
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### Total Momentum in the Center of Mass Reference Frame

For solving problems involving elastic collisions it is useful to use the center of mass reference frame as to avoid quadratic equations. However, I am confused about why the total momentum in the ...
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### How does constant thrust avoid quadratic kinetic energy accumulation?

I haven't found the right search terms for this question, so if it has been answered, references would be welcome. Suppose we start from experimental station in deep space (interstellar space if need ...
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### Lorentz Force and Apparent Conservation of Momentum Violation Useful for Unidirectional Force?

My understanding is that the apparent violation of Newton's Third Law by the Lorentz Force necessitates a description of the system that describes the "missing" momentum as being absorbed/carried by ...
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### Change in momentum in a photon collision?

Let's say I drop a ball on the ground and it bounces up. According to classical physics, once the ball hits the ground it goes trough a short phase of deceleration until the velocity reaches zero, ...
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### Can wind be defined as momentum/mass of air molecules?

In the past I thought a breeze of wind was "made" from a large amount of air molecules going all the same direction in the same speed. But it's not like that, actually this voted answer, this site, ...
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### Do gravitational waves contain actual energy and momentum? [closed]

Gravitational waves are waves in the fabric of space time and gravity is also caused by warped space time. So do gravitational waves contain actual energy and momentum?
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### deformation and displacement by a collison? [duplicate]

In an experiment by Emilie du chatelet metal balls were dropped from a height on a clay bed only to find that the displacement of the clay material was proportional to the square of velocity of the ...
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### Relationship between impact crater properties and kinetic energy? [duplicate]

William Gravesande in 1722 published an experiment in which brass balls were dropped from varying heights onto a soft clay surface. He found that a ball with twice the speed of another would leave an ...
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### Separation of two particles

An object ofass $5$ kg is projected with a velocity of $20m/s$ at an angle of $60degress$ to the horizontal. At the highest point of its path projectile explodes and breaks up into $2$ fragments of ...
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### How is momentum conserved in this electromagnetic scattering?

It is well known that verifying momentum and energy conservation in the presence of electromagnetic fields requires care as the fields themselves carry energy and momentum (see Griffiths chapter 8 for ...
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### Ball collides with another. Find velocities [closed]

A ball moving at a velocity of 5.0 m/s east when it collided with an identical ball at rest. Both balls are the same mass. The first ball moved at 60 degrees north of east. The second went 30 ...
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### If “For every action there is an equal and opposite reaction”, why does a gun not injure the shooter's hand?

If "For every action there is an equal and opposite reaction", why does a gun not injure the shooter's hand? Would not the "equal and opposite reaction" of firing a bullet be the kickback the shooter ...