Consider a stainless steel sphere of radius a = 1 mm and density = 7800 kg m⁻³ , falling through air of density p = -1.20 kg m⁻³ .
(a) Explain why the equation of the steel sphere falling with constant speed V (i.e. the limiting or terminal speed) can be written as D = (m'-m)g = 4pie a³/3(p'- p) g .
(b) Now calculate the limiting/ terminal speed of the steel sphere assuming linear resistance. also calculate the limiting/