Answer:
option A
Explanation:
given,
compression for lower setting = x
work done to compress in lower setting = 5 J
compression in higher setting, x' = 2 x
work done in higher setting = ?
Work done in compression of spring at lower setting
[tex]W = \dfrac{1}{2}kx^2[/tex]
[tex]5 = \dfrac{1}{2}kx^2[/tex]............(1)
Work done in compression of spring at higher setting
[tex]W' = \dfrac{1}{2}kx'^2[/tex]
[tex]W'= \dfrac{1}{2}k(2x)^2[/tex]
[tex]W'= 4\times \dfrac{1}{2}kx^2[/tex]
[tex]W'= 4\times W[/tex]
from equation (1)
[tex]W'= 4\times 5[/tex]
W' = 20 J
Work take for the higher setting is equal to 20 J
Hence, the correct answer is option A
