Question

a piece of cork of density 250kg/m³ is immersed in water to a depth of 1m and released. if the viscous forces due to air and water are neglected, upto what height will the cork jump adove the surface of water

A. 1m

B. 2m

C. 3m

D. 4m

Answer 1

Answer:

3m is the correct option

Answer 2

Let consider the mass of a piece  of cork = m

its volume =V.

Then

V=mρ , where ρ= density =250kg m³

While the piece of cork is released, the upward acceleration will be =a

a=upthrust-weight /mass=Vρwg−Vρg /ρV=1000g−250g /250=3g

∴ Velocity of the piece when it reaches the surface of water is u=√2ah =√2 × 3g × 1 = √6g

let consider the cork will jump to a height H above the surface of water, where H is given by

H=u² /2g=(√6g)² /2g=3m

The cork will jump  upto 3m above the surface of water

Ans:-C. 3m