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 = 100 L/sH = ?

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 7.5 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 7.5 kWQ = 100 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
PQ = 10 L/sH = 55 m

A pump delivers 10 L/s of water (ρ = 1000 kg/m³) against a total head of 55 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 10 L/sH = 55 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 60 L/sH = 56 m

A pump with an efficiency of 72% delivers 60 L/s of water (ρ = 1000 kg/m³) against a head of 56 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 60 L/sH = 56 mη = 72%g = 9.81 m/s²
Pshaft = kW
4.Medium
PQ = 50 L/sH = 20 m

In a test, a pump delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 20 m while its shaft takes 13.1 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 50 L/sH = 20 mPshaft = 13.1 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 20 L/sΔz = 35 mL = 200 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 35 m higher. The pipe is 200 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. Find the head H the pump must add.

Q = 20 L/sΔz = 35 mL = 200 mD = 100 mmf = 0.02ΣK = 8
H = m
6.Hard
250 kPa (gauge)PQ = 60 L/sΔz = 6 mL = 100 m, D = 200 mm, f = 0.025, ΣK = 4

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 6 m higher. The pipe is 100 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.025; the minor-loss coefficients add up to ΣK = 4 (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 250 kPa. Find the head H the pump must add.

Q = 60 L/sΔz = 6 mL = 100 mD = 200 mmf = 0.025ΣK = 4ptank = 250 kPa
H = m

Answer key

  1. 1. H = 7.645 m
  2. 2. Ph = 5.396 kW
  3. 3. Pshaft = 45.78 kW
  4. 4. η = 74.89 %
  5. 5. H = 50.86 m
  6. 6. H = 34.55 m

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