Q. A triangular lamina of area $A$ and height $h$ is immersed in a liquid of density $\rho$ in a vertical plane with its base on the surface of the liquid. The thrust on the lamina is
A) $\frac{1}{2}A\rho gh$
B) $\frac{1}{3}A\rho gh$
C) $\frac{1}{6}A\rho gh$
D) $\frac{2}{3}A\rho gh$
Explanation
(b) Thrust on lamina = pressure at centroid $\times$ Area
$= \frac{h\rho g}{3} \times A = \frac{1}{3}A\rho gh$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.