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 = 30 L/sH = ?

A pump delivers 30 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 30 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 30 kWQ = 30 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
Δp = 650 kPaPQ = 100 L/s

A pump raises the pressure of 100 L/s of water by 650 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 100 L/sΔp = 650 kPa
Ph = kW
3.Medium
PQ = 150 L/sH = 70 m

A pump with an efficiency of 65% delivers 150 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 = 150 L/sH = 70 mη = 65%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 60 L/sH = 44 m

In a test, a pump delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 44 m while its shaft takes 30.5 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 60 L/sH = 44 mPshaft = 30.5 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 20 L/sΔz = 39 mL = 150 m, D = 100 mm, f = 0.02, ΣK = 8

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 39 m higher. The pipe is 150 m long with an inside diameter of 100 mm and a Darcy friction factor f = 0.02; the minor-loss coefficients add up to ΣK = 8 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 80%. Find the shaft power Pshaft in kW.

Q = 20 L/sΔz = 39 mL = 150 mD = 100 mmf = 0.02ΣK = 8η = 80%
Pshaft = kW
6.Hard
350 kPa (gauge)PQ = 60 L/sΔz = 5 mL = 200 m, D = 200 mm, f = 0.022, ΣK = 5

A pump moves 60 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 5 m higher. The pipe is 200 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.022; the minor-loss coefficients add up to ΣK = 5 (entrance and exit included). Use g = 9.81 m/s². The upper tank is closed and the air above its water is at a gauge pressure of 350 kPa. Find the head H the pump must add.

Q = 60 L/sΔz = 5 mL = 200 mD = 200 mmf = 0.022ΣK = 5ptank = 350 kPa
H = m

Answer key

  1. 1. H = 101.9 m
  2. 2. Ph = 65 kW
  3. 3. Pshaft = 158.5 kW
  4. 4. η = 84.91 %
  5. 5. Pshaft = 12.64 kW
  6. 6. H = 45.7 m

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