A cup of coffee is sitting on a table in an airplane that is flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.30. Suddenly, the plane accelerates, its altitude remaining constant. What is the maximum acceleration that the plane can have without the cup sliding backward on the table?(adsbygoogle = window.adsbygoogle || []).push({});

I got 2.94 m/s^2 as my answer, but the answer is supposed to be 3.25 m/s^2.

This is how I did it:

Fsmax = (funny looking symbol for coefficient of static friction)*FN

FN = mg

Fsmax = (symbol for coefficient of static friction)*mg = ma

amax = ((symbol for coefficient of static friction)*mg)/m

amax = (symbol for coefficient of static friction*g

amax = 0.30 * 9.8 = 2.94 m/s^2

What did I do wrong?

Thanks!

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# Static Frictional Force

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