Can Formulas for Acceleration on an Inclined Plane be Written without Friction?

AI Thread Summary
The discussion revolves around deriving formulas for acceleration on an inclined plane without friction. It is established that the acceleration of an object on an incline can be calculated using the formula a = g sin(alpha), where g is the acceleration due to gravity and alpha is the angle of the incline. However, it is noted that this formula applies only if the incline is fixed, which complicates the scenario when the incline is movable. Participants emphasize the importance of drawing free body diagrams to visualize forces acting on both the small object and the triangular object. The conversation highlights the need for accurate contributions to the discussion while encouraging collaborative problem-solving.
physiker99
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Assume there is no friction in the system. Can anyone write formulas for acceleration of both the small object and the triangular object? (Gravity is downwards, no other force such as air drag etc.)

[URL=http://imageshack.us][PLAIN]http://img83.imageshack.us/img83/6036/asdasdcf6.png[/URL][/PLAIN]
 
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I would draw the free body diagrams for both objects first ... then remember "In the absence of friction and other forces (tension, applied, etc.), the acceleration of an object on an incline is the value of the parallel component (m*g*sine of angle) divided by the mass (m). This yields the equation : a = g sin (alpha)


Reference: http://www.glenbrook.k12.il.us/gbssci/Phys/Class/vectors/u3l3e.html

for the Triangular object. The applied force would be the Normal force from the smaller block ... the acceleration should come from the force parallel to the ground ..
 
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Danger86514 said:
I would draw the free body diagrams for both objects first ... then remember "In the absence of friction and other forces (tension, applied, etc.), the acceleration of an object on an incline is the value of the parallel component (m*g*sine of angle) divided by the mass (m). This yields the equation : a = g sin (alpha)
While your advice to draw free body diagrams is excellent, a = g sin (alpha) only holds if the incline is fixed. But this one can move.
 
Doc Al said:
While your advice to draw free body diagrams is excellent, a = g sin (alpha) only holds if the incline is fixed. But this one can move.

thanks, but I was only giving some points in the right direction. i was hoping that would have physiker99 think some .. in the future I will keep this in mind and just do the work for them ... i am new to the thread and was under the impression that the questions are not just answered with a blunt response.


attached is a pdf ...
 

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Danger86514 said:
thanks, but I was only giving some points in the right direction. i was hoping that would have physiker99 think some .. in the future I will keep this in mind and just do the work for them ... i am new to the thread and was under the impression that the questions are not just answered with a blunt response.
No one is suggesting that you do the work for them, but don't you think that any comment you make should at least be correct?
 
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