Constrained Motion of a Block over a Wedge

Wedge Constrained Motion is an important constrained motion which is used in framing variety of problems related to Newton’s Laws of Motion. Understanding Wedge constrained motion also helps in handling complex problems on applications of Newton’s Second Law.

Wedge constrained motion describes the motion of a block over another block of the shape of a prism or a cuboid called a wedge which slides over a smooth or rough surface. In such types of system of blocks we start our analysis by assuming the motion of first block relative to wedge and then if wedge is also moving then we consider its motion relative to the surface on which it moves.

Unlike to the case of pulley constrained motion, here students are advised to analyze the motion only by observation which is the best way to deal with such types of problems.

Misconception: Many times in problems of wedge-block systems, students apply the method of Virtual Work and it deviates the final result of the problem because in case of relative motion of block over wedge work done by normal contact force is non-zero so this method of Virtual Work is not advisable in solving the problems of wedge constrained motion whereas it work well with pulley constrained motions.

To understand the basics on how to handle wedge constrained motion in simple wedge-block systems and understanding the relations of acceleration of blocks, see the video given below –

https://youtu.be/sbmAaeVFkAw

To understand further on wedge constrained motion, pl follow the examples given below – 

https://youtu.be/P4m7tCJY6vk

https://youtu.be/O1-7BR6mick

https://youtu.be/xEJBmmtMJSs

There are several problems which are framed on combination of Wedge and Pulley constrained motion of blocks. Once you develop the basic understanding of wedge constrained motion, next step is to practice on the problems based on combination of both wedge and pulley constrained To develop understanding on the mixed cases of pulley and wedge constrained motion, see the below illustrations –

https://youtu.be/fl896CW9-pw

https://youtu.be/W8ELpaYUrSs

https://youtu.be/FHRGt_gG6Ck

https://youtu.be/NZnyGHRgFTo

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