Relative Equilibrium of Liquids Sample Problems

Sample Problems

Relative Equilibrium of Liquids

Vertical Motion

Pressure at the base of container (November 2018) - GERTC+

A water container is carried inside an elevator travelling downward.

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Force exerted at the base (November 2019) - GERTC+

A water container is carried inside an elevator travelling upward.

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Rotating Vessels

Open Vessel

Problem

An open cylindrical tank 1.20 m in diameter and 2 m high contains 1.3 m deep of water. The tank is rotated about its own vertical axis at 90 rpm. How much water is spilled in liters?

A. 130

B. 160

C. 110

D. 180

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Problem

An open cylindrical tank 1.20 m in diameter and 2 m high contains 1.3 m deep of water. The tank is rotated about its own vertical axis at 120 rpm. How much water is spilled in liters?

A. 690

B. 710

C. 730

D. 650

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Problem

An open cylindrical tank 1.20 m in diameter and 2 m high contains 0.8 m deep of water. The tank is rotated about its own vertical axis at 120 rpm. How much water is spilled in liters?

A. 105.87

B. 136.98

C. 124.12

D. 156.98


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Height of tank to avoid spillage (November 2018) - GERTC+

Open tank containing water and rotated about its axis.

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Volume spilled on an open tank (November 2019) - GERTC+

Open cylindrical tank 2/3 full of water.

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Closed Vessel

Force on top of a closed tank (November 2019)- GERTC+

Closed tank filled with water and rotated about its axis.

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Force on top of a closed tank (November 2019)- GERTC+

Closed tank filled with water and rotated about its axis.

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Situation

A closed cylindrical vessel 1.2 m in diameter, 1.8 m high and 2/3 full of water has a small hole at the center of the top cover. If it is rotated at 90 rpm.

  • Compute the maximum pressure at the bottom of the tank.

A. 21.54 kPa

B. 19.93 kPa

C. 15.63 kPa

D. 32.56 kPa

  • Compute the minimum pressure at the bottom of the tank.

A. 3.94 kPa

B. 2.54 kPa

C. 5.69 kPa

D. 6.98 kPa

  • Determine the discharge through a 25-mm-sharp-edged orifice at the bottom of the vessel located 300mm from the vertical axis of the blinder vessel. C = 0.60.

A. 2.56 L/s

B. 3.25 L/s

C. 1.17 L/s

D. 1.87 L/s

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