Question

When a 20 kg load is applied to a uniform string,
then in equilibrium elongation of the string is 5 mm
from its natural length. When it is loaded with 40
kg then its equilibrium elongation from its natural
length will be
(1) 5 mm
(2) 10 mm
(3) 15 mm
(4) 20 mm​

Answer 1

Answer:

(2) 10 mm

elongation (l)=FL/AY

F-Force/Load

L-original/natural length

A Area

Y-Young's Modulus

first case

5=20×L/AY

X=40×L/AY

dividing both equations

5/X=1/2

x=10mm