A block of mass $$m$$ is placed on a surface having vertical crossection given by $$y=x^2 / 4$$. If coefficient of friction is 0.5, the maximum height above the ground at which block can be placed without slipping is:

Three blocks $$A, B$$ and $$C$$ are pulled on a horizontal smooth surface by a force of $$80 \mathrm{~N}$$ as shown in figure

The tensions T$$_1$$ and T$$_2$$ in the string are respectively :

All surfaces shown in figure are assumed to be frictionless and the pulleys and the string are light. The acceleration of the block of mass $$2 \mathrm{~kg}$$ is :

Given below are two statements :

Statement (I) : The limiting force of static friction depends on the area of contact and independent of materials.

Statement (II) : The limiting force of kinetic friction is independent of the area of contact and depends on materials.

In the light of the above statements, choose the most appropriate answer from the options given below :