If You Took A Sphere Of A Certain Diameter, And Peeled Off A Uniform Outer Layer, Like The Peel How Do You Find Out By How Much It Would Reduce The Total Surface Area Of The Object?
Also, how do you generally calculate the area of a sphere?
The surface area of a sphere of radius 'r' is given by: surface area = 4*pi*r^2
So if you peel of a layer, lets say of thickness r1 then the surface area equation would look as follows - 4*pi*(r-r1)^2 If you wanted to calculate the voume of a sphere it would be - 4/3*pi*r^3, in this case 4/3*pi*(r-r1)^3
Raimi is correct that the new area of a sphere of radius r with a layer of thickness t peeled off is 4*pi*(r-t)^2. So, the decrease in the area of the sphere is 4*pi*(r^2-(r-t)^2) = 4*pi*(2rt-t^2) = 4*pi*t*(2*r-t). If r is enough larger than t so that 2*r-t is approximately 2*r, then the reduction in area is approximately 8*pi*r*t.