IIT JEE , AIEEE Forum - Physics , Mechanics

spiderhunt

A block is kept on a horizontal table. The table is undergoing S.H.M of frequency 3 Hz in a horizontal plane. The cofficient of static friction between block and the table surface is 0.72 . Find the maximum amplitude of the table at which the block does not slip on the surface.

iam_quantized

THE MAX ACCN OF TABLE IS Aw^2.....AT THIS PT VEL IS 0 ..AN FORCE IS MAX CLEARLY THE TABLE EXERTS THE SAE FORCE ON THE BLOCK WHICH WILL PREVENT SLIPPING IF AW^2=.72g
A=.72g/W^2.

spiderhunt

ANS IS 2 cm

edison

Maximum value of acceleration of the table is at amplitudes which is given by

a_max= -w²A (at amplitudes and directed towards mean position as shown by -ve sign)

So force on the block = ma_max

Where m is mass of the block.

Condition required so that the block does not slip is

mg = ma_maxwhere

is coefficient of static friction

or

mg = ma_max

or

g = -w²A

or A = -

g / w²HERE -VE SIGN CAN BE DROPPED AS IT SIMPLY SHOWS THE DIRECTION OF FORCE AND THUS ACCELERATION TOWARDS THE MEAN POSITION

SO A =

g / w²OR A = 0.72 g / w²

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