Question

A plastic ball is suspended inside liquid filled in a closed cylindrical container shown in figure. The elongation in spring is 1 mm. The cylinder is now rotated about vertical axis shown with angular velocity w= $\sqrt { \frac { \mathrm { g } } { \mathrm { a } } }$. Assuming that length of spring b<< a, elongation in spring will be –

• A. 1.7 mm
• B. 2 mm
• C. 1 mm
• D. 1.4 mm

Answer 1

Answer: (D)

1.4 mm

Answer 2

g_eff = =

\ = Þ

(x¢ = Final elongation)

= 1.4 mm