In order to know the amount of steel required to make one shot, we need to find the volume of a sphere.
The formula of the volume of a sphere is

where r is the radius of the sphere
r is half of the diameter
r=10/2=5 cm
then we substitute the values
![V=(4)/(3)\pi(5)^3=(4)/(3)\pi(125)=523.6\operatorname{cm}^3]()
We will need 523.6cm^3 of steel