A stationary upright cone has a taper angle θ=45∘\theta=45^{\circ}θ=45∘, and the area of the lateral surface S0=4.0 m2S_{0}=4.0 \mathrm{~m}^{2}S0=4.0 m2. Find: its taper angle; (b) its lateral surface area, in the reference frame moving with a velocity v=(4/5)cv=(4 / 5) cv=(4/5)c along the axis of the cone.