Question

What is the extension of spring P in figure (iii)?

• A. 6 cm
• B. 9 cm
• C. 12 cm
• D. 15 cm

Answer 1

The correct option is C 12 cm

from fig.(1)length of spring l$=3cm$ andfrom fig.(2)$x=6-3=3cm;k=\frac{F}{x}=\frac{2}{3}$
in fig.(3}$F=8N;x=\frac{F}{k}=\frac{8}{2/3}=12cm$
hence, the extension of spring P in figure is 12cm