If the mass of an object is doubled,what will be the effect on the coefficient of friction?

The limiting value of static friction between two contact surfaces is ...........

$A$ block of mass $4 \text{ kg}$ is placed on a horizontal surface having coefficients of static and kinetic friction as $0.5$ and $0.4$ respectively. If a force of $4 \text{ N}$ is applied parallel to the horizontal surface, then the force of friction acting on the body will be $\left[g = 10 \text{ m/s}^2\right]$ (in $\text{ N}$)

How does static friction oppose motion? On which factors does the value of the coefficient of friction depend?

$A$ uniform chain of $6 \, m$ length is placed on a table such that a part of its length is hanging over the edge of the table. The system is at rest. The coefficient of static friction between the chain and the surface of the table is $0.5$. The maximum length of the chain hanging from the table is.......$m.$

To avoid slipping while walking on ice,one should take smaller steps because of the