A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)): 
Heinrich Kayser, the German physicist was the first to coin the term adsorption. Adsorption can be explained as a surface phenomenon where particles remain attached on the top of a material. Generally, it comprises the molecules, atoms, liquid, solid in a dissolved stage, even the ions of a gas that are attached to the surface. Much to our surprise, the consequence of surface energy i.e. adsorption is present in biological, physical, chemical, and natural systems and are used in many industrial applications.
