How do I calculate the acceleration of a moving container on a specular surface?

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To calculate the acceleration of a horizontally moving open container with water, the angles of incidence and reflection are given as α=40 degrees and β=20 degrees. The discussion emphasizes the importance of analyzing the forces acting on a small parcel of water within the container and suggests drawing a free body diagram to visualize these forces. There is a concern about the accuracy of the provided diagram, as it does not depict the water surface correctly. Participants highlight the need to consider the frame of reference of the accelerating container when determining the forces involved. Overall, understanding the dynamics of the water's surface is crucial for solving the problem accurately.
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Homework Statement


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It's open container with water which moves horizontally. It moves with some acceleration. Angle of incidence (α) and angle of reflection(β) on water are given (α=40 deg., β=20 deg.). We need to find container's acceleration.

Homework Equations


a=(v2-v1)/t (?)

The Attempt at a Solution



I've built angles of incidence and angles of reflection for both cases when v=0 and a=0 but what do to further is a big question for me (maybe this way of solution is wrong).

I'll be grateful for the help
 
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Is this your own diagram or was it provided?
Have you stated the question, word for word, as it was given to you?
I ask because it would be unusual for a horizontally accelerating body of water to have a horizontal surface.
 
haruspex said:
Is this your own diagram or was it provided?
Have you stated the question, word for word, as it was given to you?
I ask because it would be unusual for a horizontally accelerating body of water to have a horizontal surface.
It's open container with water on car. Diagram was provided without vector a
 
Facelam said:
It's open container with water on car. Diagram was provided without vector a
Ok. Distrust the diagram.
Consider a small parcel of water on the surface, or maybe some particle floating there, just submerged. Draw a free body diagram for it. What forces are there? How do these forces account for the acceleration?
Alternatively, if you are comfortable with non-inertial frames, in the frame of reference of the car what are the forces?
 
haruspex said:
Ok. Distrust the diagram.
Consider a small parcel of water on the surface, or maybe some particle floating there, just submerged. Draw a free body diagram for it. What forces are there? How do these forces account for the acceleration?
Alternatively, if you are comfortable with non-inertial frames, in the frame of reference of the car what are the forces?
fa31e3ecf18e4bdab489b9cdb170fe63.png

It's a copy of diagram and it moves horizontally
 
Facelam said:
fa31e3ecf18e4bdab489b9cdb170fe63.png

It's a copy of diagram
this diagram shows the container, not the water surface. Note that the incident and reflected rays are not shown meeting.
In your original diagram you assumed acceleration was to the left.
 
haruspex said:
this diagram shows the container, not the water surface. Note that the incident and reflected rays are not shown meeting.
In your original diagram you assumed acceleration was to the left.
There is water inside that container. Yeah, and I can't understand why (how is it possible?).
Acceleration to the left is my supposition
 
Facelam said:
There is water inside that container. Yeah, and I can't understand why (how is it possible?).
Acceleration to the left is my supposition
Yes, there is water inside, but the diagram does not show it, so you do not know what the surface looks like.
Please try to answer my questions in post #4.
 
haruspex said:
Yes, there is water inside, but the diagram does not show it, so you do not know what the surface looks like.
Please try to answer my questions in post #4.
6bf7b3cf048f4767bc244ad181cd9cbc.png

Don't understand why I didn't see it
 
  • #10
Facelam said:
6bf7b3cf048f4767bc244ad181cd9cbc.png

Don't understand why I didn't see it
That looks much better.
 
  • #11
haruspex said:
That looks much better.
Thank you for help!
 
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