When two surfaces are coated with a lubricant, then they
A
Stick to each other
B
Slide upon each other
C
Roll upon each other
D
None of these
AIIMS 2001, Easy
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B
Slide upon each other
b (b)Surfaces always slide over each other.
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$Assertion$ : There is a stage when frictional force is not needed at all to provide the necessary centripetal force on a banked road.
$Reason$ : On a banked road, due to its inclination the vehicle tends to remain inwards without any chances of skidding.
A disc with a flat small bottom beaker placed on it at a distance $R$ from its center is revolving about an axis passing through the center and perpendicular to its plane with an angular velocity $\omega$. The coefficient of static friction between the bottom of the beaker and the surface of the disc is $\mu$. The beaker will revolve with the disc if
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