What is the force required (in Newtons) to hold a spherical balloon stationary in water at a depth of H from the air-water iterface? The balloon is of radius 0.1 m and is filled with air.
A. $$\frac{{4\pi {\text{g}}}}{3}$$
B. $$\frac{{0.01\pi {\text{gH}}}}{4}$$
C. $$\frac{{0.01\pi {\text{gH}}}}{8}$$
D. $$\frac{{0.04\pi {\text{gH}}}}{3}$$
Answer: Option A
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A. Thermal conductivity
B. Electrical conductivity
C. Specific gravity
D. Electrical resistivity
A. $$\frac{{\text{V}}}{{{{\text{V}}_{\max }}}} = {\left( {\frac{{\text{x}}}{{\text{r}}}} \right)^{\frac{1}{7}}}$$
B. $$\frac{{\text{V}}}{{{{\text{V}}_{\max }}}} = {\left( {\frac{{\text{r}}}{{\text{x}}}} \right)^{\frac{1}{7}}}$$
C. $$\frac{{\text{V}}}{{{{\text{V}}_{\max }}}} = {\left( {{\text{x}} \times {\text{r}}} \right)^{\frac{1}{7}}}$$
D. None of these
A. d
B. $$\frac{1}{{\text{d}}}$$
C. $$\sigma $$
D. $$\frac{l}{\sigma }$$
A. $$\frac{{4\pi {\text{g}}}}{3}$$
B. $$\frac{{0.01\pi {\text{gH}}}}{4}$$
C. $$\frac{{0.01\pi {\text{gH}}}}{8}$$
D. $$\frac{{0.04\pi {\text{gH}}}}{3}$$
The force required = Buoyancy force - gravitational force
Buoyancy force = mass of fluid displaced x g
mass of fluid displaced = density of fluid x volume of the balloon = 1000 x 4/3 x pi x (r^3) = 4/3 pi
Buoyancy force = 4/3 x pi x g
Gravitational force = mass of the balloon x g
mass of the balloon = density of air x volume = 1.225 x 4/3 x pi x (r^3) = 0.001225 x 4/3 pi
Gravitational force = 0.001225 x 4/3 x pi x g
The force required = Buoyancy - gravitational = 4/3 x pi x g (1 - 0.001225) = 4/3 x pi x g x 0.998 = 4/3 x pi x g
Pls explain