In a container, the velocity of water flowing through a hole at a dept...
Velocity of water flowing through a hole at a depth h from the surface of water is 5 m/s. We need to find the velocity of water flowing through the same hole if it is placed at a depth 4h from the surface of water.
Explanation:Bernoulli's equation:
Bernoulli's equation states that the sum of pressure, kinetic energy, and potential energy per unit volume of a fluid is constant at any point in the fluid.
P + ρgh + ½ρv2 = constant
Where P is the pressure of the fluid, ρ is the density of the fluid, g is the acceleration due to gravity, h is the height of the fluid above a reference point, and v is the velocity of the fluid.
Application of Bernoulli's equation:
We can apply Bernoulli's equation to find the velocity of water flowing through the hole at a depth 4h from the surface of water.
At depth h: P1 + ρgh + ½ρv12 = constant
At depth 4h: P2 + ρg(4h) + ½ρv22 = constant
Since the hole is at the same level in both cases, the pressure at the hole is the same in both cases.
P1 = P2
We can cancel out the constant term on both sides of the equation.
ρgh + ½ρv12 = ρg(4h) + ½ρv22
Rearranging the equation, we get:
v2 = sqrt(v12 + 6gh)
Substituting the given values, we get:
v2 = sqrt(52 + 6*9.81*4h) = 10 m/s
Therefore, the velocity of water flowing through the hole at a depth 4h from the surface of water is 10 m/s, which is option (b).