SOLUTION: A hollow metal sphere has an internal radius of 20 cm and an external radius of 30 cm. Given that the density of the metal is 7.8 g/cm^3 (gramme per cm cube), find the weight of th

Algebra ->  Surface-area -> SOLUTION: A hollow metal sphere has an internal radius of 20 cm and an external radius of 30 cm. Given that the density of the metal is 7.8 g/cm^3 (gramme per cm cube), find the weight of th      Log On


   

Question 447452: A hollow metal sphere has an internal radius of 20 cm and an external radius of 30 cm. Given that the density of the metal is 7.8 g/cm^3 (gramme per cm cube), find the weight of the sphere.
Found 2 solutions by www.achukanjosh@gmail.com, mananth:
Answer by www.achukanjosh@gmail.com(3) About Me  (Show Source):
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
External volume - Internal volume)( * density = weight of sphere
4/3 pir^3= volume
r1= 30
r2=20
4/3pi(r1^3-r2^3)= volume of shell
4/3 * pi ( 27000-8000)
4/3 * pi *19000
== 79,587.01 cu.cm
....
Density = 7.8gms/cu.cm
79,587.01*7.8=620,778 gms
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