There is formation of layer of snow x cm thick on water, when the temperature of air is `-theta^(@)C` (less than freezing point). The thickness of layer increases from x to y in the time r, then the value of t is given by

Options

A. `((x+y)(x-y)rho L)/(2k theta)`
B. `((x-y)rho L)/(2k theta)`
C. `((x+y)(x-y)rho L)/(k theta)`
D. `((x-y)rho Lk)/(2 theta)`

Answer

A

Explanation

Since, t= `(rho L)/(2k theta)(x_2^2-x_1^2)`
`therefore t=(rhoL)/(2k theta)(x^2-y^2)=(rho L (x+y)(x-y))/(2K theta)`