A solid circular metallic disc of radius 12 inches and thickness 4 inches is melted and shaped into a solid disc of radius 16 inches. What is the thickness of the new disc in inches?
This questions was previously asked in
EPFO APFC 2023
Explanation:
To determine the thickness of the new disc, we'll use the principle of volume conservation since the metal is simply reshaped:
1. Volume of the original disc:
V = pi * {radius}2 * {thickness} = pi * 122 * 4 = 576 pi
2. Volume of the new disc:
V = pi * {radius}2 * {thickness} = pi * 162 * t = 256pi * t
Setting the volumes equal (since the material is conserved):
576pi = 256pi * t
Divide both sides by 256pi to solve for t :
t = 2.25
Answer: Option 2 - 2.25
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By: Babita