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Grade 11Mechanics

a cylindrical vessel of cross section area 1000cm² , is fitted with piston of mass 10 kg , and filled with water completely . a small hole of cross section area 10mm² us opened at a point 50cm deep from the lower surface of piston . then find velocity of efflux

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9 Years agoGrade 11
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ApprovedApproved Tutor Answer1 Year ago

To find the velocity of efflux of water from the hole in the cylindrical vessel, we can use Torricelli's theorem. This theorem states that the speed of fluid flowing out of an orifice under the influence of gravity is given by the formula:

Understanding the Variables

Before we dive into the calculations, let's identify the key variables involved:

  • Cross-sectional area of the vessel (A): 1000 cm²
  • Mass of the piston (m): 10 kg
  • Cross-sectional area of the hole (a): 10 mm² (which is 0.001 m²)
  • Depth of the hole (h): 50 cm (which is 0.5 m)
  • Acceleration due to gravity (g): approximately 9.81 m/s²

Applying Torricelli's Theorem

According to Torricelli's theorem, the velocity of efflux (v) can be calculated using the formula:

v = √(2gh)

Here, h is the height of the water column above the hole, which is 0.5 m in this case. Plugging in the values:

Calculating the Velocity

Now, substituting the known values into the equation:

v = √(2 * 9.81 m/s² * 0.5 m)

Calculating the product inside the square root:

v = √(9.81 m/s²)

Now, taking the square root:

v ≈ 3.13 m/s

Conclusion

The velocity of efflux of water from the hole in the cylindrical vessel is approximately 3.13 m/s. This result illustrates how the height of the water column directly influences the speed at which the water exits the vessel. The greater the height, the higher the velocity, which is a fundamental principle in fluid dynamics.