14. What length of a solid cylinder 2 cm in diameter must be
taken to recast into a hollow cylinder of length 16 cm,
external diameter 20 cm and thickness 2.5 mm?
Answers
Answer:
ANSWER
Given diameter of solid cylinder is 2cm.
Radius of solid cylinder, r=1 cm.
Volume of solid cylinder is πr2h
=π×12×h=πh→(1)
Length of hollow cylinder, H=15 cm
External diameter =20 cm
External radius =10 cm
Thickness =0.25 cm
Internal radius =10–0.25=9.75 cm
Volume of hollow cylinder =π[10²–(9.75)²]×15
=15π×19.75×0.25→(2)
From (1) and (2), we get
πh=15π×19.75×0.25
Hence, h=15×19.75×0.25=74.06cm
Explanation:
PLS MARK AS BRAINLIEST
Here's Your Answer Mate!
Given diameter of solid cylinder = 2 cm
Radius of solid cylinder, r = 1 cm
Volume of solid cylinder = πr2h
= π × 12 × h = πh → (1)
Length of hollow cylinder, H = 16 cm
External diameter = 20 cm
External radius = 10 cm
Thickness = 2.5 mm = 0.25 cm
Internal radius = 10 – 0.25 = 9.75 cm
Volume of hollow cylinder = π[102 – (9.75)2] × 16
= 16π × 19.75 × 0.25 → (2)
From (1) and (2), we get
Πh = 16π × 19.75 × 0.25
∴ h = 16 × 19.75 × 0.25 = 79 cm