Your Marlin model 989 which was a semi auto promotional model will range in price from 75-150 dollar,depending on overall condition.
The value of Kw is 1.0 times 10-14 m2
The value is 10-8 W/m2.
400-410 GPa, 109 N/m2
That depends on the value you give to 'm'.
experimental value of diffusion coefficient of acetone is 0.037 m2/s
try Numrich Gun Parts Corp.If they do not have one,maybe Marlin itself may have a few still in stock.E-bay would be another good place to find a stock for your rifle.
It depends on the value of m. Multiply m by itself.