Why does a wave pulse invert when it hits a fixed boundary on a string?

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A wave pulse traveling down a rope inverts upon hitting a fixed boundary due to the interaction of forces at the boundary. When the upward 'kink' in the rope reaches the wall, it exerts an upward force, prompting the wall to exert a downward force on the string. This results in the reflected wave being inverted. The conservation of momentum is maintained throughout this process, as the wave's energy is transferred to the boundary and then reflected back. Understanding the resultant displacement at the wall clarifies the direction of the reflected wave.
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Hi, please could someone explain why a wave pulse traveling down a rope inverts when it strikes a fixed boundary. Is it something to do with conservation of momentum?
 
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There are no any problems with conservation of momentum: if we consider a longitudinal wave, then a wave pulse will push a fixed boundary which pushes the Earth which changes slightly its orbit.
 
At least two ways of understanding it...

(1) Assume (though we don't have to) that the wave is transverse and in the vertical plane, and that the pulse is an upward 'kink' in the rope. When the start of the kink reaches the wall it exerts an upward force on the wall. So what is the direction of the force that the wall exerts on the string (initiating the reflected wave)?

(2) What is the RESULTANT displacement of the string at the wall due to the incident and reflected waves? What therefore must be the direction of the reflected wave at the wall?
 

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