Question

1. Two thin circular discs of radii 3 cm and 4 cm lie
in a liquid at the same depth. The thrusts on
them are in the ratio
(b) 4:3 (c) 13:2 (d) 9:16
(a) 3:4​

Answer 1

Answer:

d) 9:16

Explanation:

The thrusts act on these circular disc

↓dependent on

area covered by the circular disc and density of the fluid

Given that,

1. radii of those two circular disc are 3cm and 4cm
2. lie in the liquid at the same depth

therefore the area covered by two disc

= πr^2

so, the ratio of their thrust will be

= π3^2 : π4^2

= 3^2 : 4^2

= 9 : 16

hence , obtion ( d) 9 : 16 is correct