A vibration platform oscillates up and down with a fixed amplitude of 8.1 cm and a controlled frequency that can be varied. If a small rock of unknown mass is placed on the platform, at what frequency will the rock just begin to leave the surface so that it starts to clatter?

Explanation:

The rock will begin to leave the surface when reaction force becomes zero or when the acceleration of the  plate-form downwards and gravitational acceleration acting on mass m becomes equal .

acceleration of plate- form ( maximum ) = ω²A , A is amplitude and  ω is angular frequency .

ω²A  =  g

4π² n² = g

n² = g / 4π²

9.8 / 4 x 3.14²

= .2484

n = .5

gravity

explanation:

the entire statement is true and correct.  

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