Accelerating Platform, Tilting Object

[Master J]

A cylindrical tin, full of water, is sitting on a platform. What is the maximum acceleration of the platform that will not cause the can to tilt?

The dimensions of the tin are known.


I'm unsure how to approach the question first off. My reasoning so far has been along the line of this:

The force from the accelerating platform, ma, will tend to rotate the object, since it is asymetrical, it only acts on the bottom of the tin. But, where is the fulcrum? The tin is a symmetrical body, so should the fulcrum be in its centre? If that IS the case, should I look at moments etc?

Any way of enlightening me on this will be greatly appreciated. Thanks!

 

[gneill]

One way you might think of this problem is that the acceleration a and the gravitational acceleration g, when added together, effectively tilt the direction of "down" -- down is the direction of the net acceleration. The question then becomes, how far over can you tilt the tin before its center of mass is no longer over its base?

 

[Master J]

Bingo...I had thought of that approach, wasnt too sure tho.

I get a coefficient of friction to stop it sliding also as 1.9...very high! Do materials have coefficients this high? I thought they were usually no greater than 1?

 

[gneill]

Bingo...I had thought of that approach, wasnt too sure tho.

I get a coefficient of friction to stop it sliding also as 1.9...very high! Do materials have coefficients this high? I thought they were usually no greater than 1?

Maybe it's actually glued down! I suppose that it's possible to have two surfaces that really grab each other -- take velcro as an extreme case.

 

[Master J]

Yea I guess so. Actually, looking here in the forums I see someone has mentioned drag racer tires having over 4!