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 \( g = 10 \, \text{m/s}^2 \)): 
Polymerization is a chemical reaction in which a large number of monomer molecules combine to produce a polymer. A polymerization can yield macromolecules with a linear or branching structure. They can also take the form of a three-dimensional complicated network.
Polymerization reactions are divided into two groups, namely, Addition polymerization (chain reaction) and condensation reaction (step reaction).