a sphere wall is 20mm thick, inside diameter is 10M. What is the mass of steel if the density is 7850Kgm3?

find volume of the shell

r1 = 10 m = 1000 cm = 10000 mm
V1 = (4/3)π(10000)^3 = ....

r2 = 10000 - 20 = 9980 mm
V2 = (4/3)π(9980)^3 = ....

volume of shell = V1 - V2 = ....

7850 kg/m^3
= 7850000 g/(100^3 cm^3)
= 7.85 g / cm^3
= .00785 g/ mm^3

I will let you do all the button-pushing
Use the memories in your calculator, don't round off any intermediate numbers, let your machine do the work for you

To find the mass of the steel sphere wall, we need to first calculate the volume of the steel used.

The wall thickness is given as 20mm, which means that the outer diameter of the sphere is 10m + 2 * 20mm = 10.04m.

Now, we can calculate the volume of the steel shell. The formula for the volume of a hollow sphere is:

V = (4/3) * π * (R1^3 - R2^3)

Where:
V is the volume of the shell,
π is a mathematical constant approximately equal to 3.14159,
R1 is the radius of the outer sphere (10.04m/2 = 5.02m), and
R2 is the radius of the inner sphere (10m/2 = 5m).

Using the values in the formula, we get:

V = (4/3) * π * ((5.02^3) - (5^3))

Next, we need to convert the volume from cubic meters to cubic millimeters since the density is given in kilograms per cubic meter. There are 1,000,000 cubic millimeters in a cubic meter, so we multiply the volume by 1,000,000 to convert it:

Vmm = V * 1,000,000

Now that we have the volume in cubic millimeters, we can calculate the mass using the density of steel. The formula for mass is:

M = Vmm * density

Substituting the values into the formula, we get:

M = Vmm * 7850

Now, we can solve for M to find the mass of the steel sphere wall.