A hollow spherical metallic ball made of metal of thickness 10mm is cut into two equal halves. If the outer diameter of the ball is 12cm. What is the total surface area of one part?

Answer 1

The surface area of a sphere is 4πr² , the inner surface radius of the sphere r_in and

r_{in = 12 cm - ( 10 mm . 1 cm/10 mm) = 12 cm - 1 cm = 11 cm}

_{The inner surface are is = 4 π ( 11 cm)}² _{= 1520.53 cm}² _{, and the total surface area of one part is = 1520.53 / 2 = 760.26 cm}²