Example 3: 
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The box B sits on the bed of a truck which is going around a turn of  radius 
. At this instant the truck has a speed 
. If the coefficient of friction between B and the bed is 
, calculate the maximum rate at which the truck’s speed can
increase without making the box slip.
Solution:
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Slip condition,
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Substitute (2) into (4), we get

Substitute (5) into (1) and (3), we get


Substitute (8) into (7), we get

