Q: A cylindrical object of outer diameter 10cm, height 20cm and density 8000 kgm-3 is supported by a vertical spring and is half dipped in water as shown in figure. Find the elongation of the spring in equilibrium condition.(k= 500 N/m)
(a) 23.5 cm
(b) 5.23 cm
(c) 25.3 cm
(d) 24.2 cm
Ans: (a)
Sol: At equilibrium ,
Apparent weight of the object = Spring force
Weight – buoyancy = k x
$\large x = \frac{Weight – buoyancy}{k}$