Calculate the maximum acceleration (in $m s^{-2}$) of a moving car so that a body lying on the floor of the car remains stationary. The coefficient of static friction between the body and the floor is $0.15$ $(g = 10 m s^{-2})$.

$A$ body of mass $4\, kg$ is at rest on a horizontal table. The coefficient of friction between the body and the table is $0.2$. $A$ horizontal force of $6\, N$ is applied on the body. The acceleration of the body is .......... $m/s^2$.

$A$ block of weight $W$ is held against a vertical wall by applying a horizontal force $F$. The minimum value of $F$ needed to hold the block is $[\mu < 1]$.

$A$ block of mass $M$ rests on a rough horizontal table. $A$ steadily increasing horizontal force is applied such that the block starts to slide on the table without toppling. The force is continued even after sliding has started. Assume the coefficients of static and kinetic friction between the table and the block to be equal. The correct representation of the variation of the frictional force $f$,exerted by the table on the block with time $t$ is given by

Explain: "Static friction force opposes impending motion".

The limiting friction between two bodies in contact is independent of