$1\mathrm{.}1$ Bonchem, in South Africa, has found that the energy required to reduce the mean particle diameter of particulate matter from of $1cm$ to $0\mathrm{.}3cm$ is $11kJk{g}^{-1}.$ Calculate the energy requirement to reduce the same particles from a diameter of $0\mathrm{.}1cm$ to $0\mathrm{.}01cm$ assuming:

a$)$ Kick's Law,

b$)$ Rittinger's Law,

c$)$ Bond's Equation.

$1\mathrm{.}2$ Mr Borders used a pair of crushing rolls for maize milling, maize grains equivalent to $38mm$ spheres in diameter were crushed to $12\mathrm{.}7mm.$ If the coefficient of friction is $0\mathrm{.}29,$ what should the diameter of the rolls be$?$

$(5)$