Pumps & pump power worksheet with answers

Free printable Pumps & pump power worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
PQ = 20 L/sH = 28 m

A pump delivers 20 L/s of water (ρ = 1000 kg/m³) against a total head of 28 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 20 L/sH = 28 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 25 L/sH = 77 m

A pump delivers 25 L/s of water (ρ = 1000 kg/m³) against a total head of 77 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 25 L/sH = 77 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 50 L/sH = 70 m

A pump with an efficiency of 80% delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 70 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 50 L/sH = 70 mη = 80%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 20 L/sH = 54 m

In a test, a pump delivers 20 L/s of water (ρ = 1000 kg/m³) against a head of 54 m while its shaft takes 13.6 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 20 L/sH = 54 mPshaft = 13.6 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 20 L/sΔz = 20 mL = 200 m, D = 100 mm, f = 0.022, ΣK = 6

A pump moves 20 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 20 m higher. The pipe is 200 m long with an inside diameter of 100 mm and a Darcy friction factor f = 0.022; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 85%. Find the shaft power Pshaft in kW.

Q = 20 L/sΔz = 20 mL = 200 mD = 100 mmf = 0.022ΣK = 6η = 85%
Pshaft = kW
6.Hard
PQ = 30 L/sΔz = 9 mL = 200 m, D = 150 mm, f = 0.02, ΣK = 6

A pump moves 30 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 9 m higher. The pipe is 200 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.02; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 82%. Find the shaft power Pshaft in kW.

Q = 30 L/sΔz = 9 mL = 200 mD = 150 mmf = 0.02ΣK = 6η = 82%
Pshaft = kW

Answer key

  1. 1. Ph = 5.494 kW
  2. 2. Ph = 18.88 kW
  3. 3. Pshaft = 42.92 kW
  4. 4. η = 77.9 %
  5. 5. Pshaft = 8.431 kW
  6. 6. Pshaft = 4.952 kW

Full step-by-step solutions: practise this topic on examproblems.com.