"Published in Newark, California, USA"
A piece of lead pipe is 50 ft. long. Its outer radius is 2 in., and it is ¼ in. thick. Into how many spherical bullets ¼ in. in diameter can be melted?
Solution:
To illustrate the problem, it is better to draw the figure as follows
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| Photo by Math Principles in Everyday Life |
If the thickness of a lead pipe is ¼ in., then the inner radius is
Hence, the volume of a lead pipe is
If a lead pipe is melted and then converted into spherical bullets of diameter ¼ in., the volume of a piece of spherical bullet is
Therefore, the number of spherical bullets in a lead pipe is
