Length of wire = (π x (8^2 - 6^2) x 35) / (π x 2.8^2)
= (504 x 35) / (7.84)
= 6,420 cm
A hollow cylindrical iron pipe with external and internal radii 8cm and 6cm respectively and length is 35cm is melted and recast into a solid wire of thickness 2.8cm. Find the length of wire
2 answers
volume of original pipe = π(8^2 - 6^2)(35)
"solid wire of thickness 2.8cm" to me suggests that the diameter is 2.8
so the radius would be 1.4
length of new wire = π(1.4)^2 (L) , where L is the length of the new wire
π(1.4)^2 (L) = π(8^2 - 6^2)(35)
L = (8^2 - 6^2)(35) / 1.96
= 500
looking at the robot's last two lines ....
...
= (504 x 35) / (7.84)
= 6,420 cm
How can it even get that arithmetically ???
"solid wire of thickness 2.8cm" to me suggests that the diameter is 2.8
so the radius would be 1.4
length of new wire = π(1.4)^2 (L) , where L is the length of the new wire
π(1.4)^2 (L) = π(8^2 - 6^2)(35)
L = (8^2 - 6^2)(35) / 1.96
= 500
looking at the robot's last two lines ....
...
= (504 x 35) / (7.84)
= 6,420 cm
How can it even get that arithmetically ???
14 answers