Question

A solid of density 2.7gcm-3 and of volume 0.0015 m3

is completely immersed in alcohol of density 800 kgm-3

. Calculate in

SI unit:

(i) Weight of the solid.

(ii) Upthrust on solid.

(iii) Apparent weight of the solid in alcohol.
​

Answer 1

Given info : A solid of density 2.7 g/cm³ and of volume 0.0015 m³ is completely immersed in alcohol of density 800 kg/m³.

To find :

1. weight of the solid
2. upthrust on solid
3. apparent weight of the solid in alcohol.

solution : weight of the solid = density of the solid × volume of solid × g

= 2.7 g/cm³ × 0.0015 m³ × 10 m/s²

= 2.7 × 10³ kg/m³ × 0.0015 m³ × 10 m/s²

= 40.5 N

upthrust on solid = weight of alcohol displaced.

= Vρg

= 0.0015m³ × 800 kg/m³ × 10 m/s²

= 12 N

apparent weight of the solid in alcohol = actual weight of solid - upthrust

= 40.5 N - 12 N

= 28.5 N