assuming that the alpha particles first travel through 2cm of air how dep will the alpha particle penetrate into an alum

[answerhappygod]

assuming that the alpha particles first travel through 2cm of
air how dep will the alpha particle penetrate into an aluminum slab
if incident angle of 35 deg with respect to the surface normal.
Assume linear energy loss

rho_air = .0001225 g/cm^3
A_air = 14.74
rho_Al = 2.7 g/cm^3
A_Al = 27