Worksheet Grade 7 Engineering & Design

Windrow Booster Pump: Pressure-Zone Design Constraints

Students size a fictional town's booster pump, turning water height into pressure and checking each neighborhood against a service pressure range.

Objectives

  1. Students will convert water height in feet to pressure in psi using the rate 0.433 psi per foot.
  2. Students will check each neighborhood's pressure against a service range and size a booster pump to fix a low zone.

Vocabulary

Key words: pressure, booster pump, psi, constraint

Teacher overview

Water pressure comes from height. The higher the water sits above a home, the more pressure that home gets. This worksheet uses the fictional town of Windrow, where a hilltop neighborhood keeps losing pressure. Students find the pressure at each spot, check it against the town's service range, and size a booster pump to fix the low zone. A common misconception is that a pump is needed everywhere; in fact, homes below the tower already have plenty of pressure, and only the high neighborhoods need a boost.

Answer Key

  1. Answer: 43 psi.
    100 feet × 0.433 psi per foot = 43.3, which rounds to 43 psi.

  2. Answer: 13 psi.
    The water surface is 30 feet above Hilltop. 30 × 0.433 = 12.99, which rounds to 13 psi.

  3. Answer: 7 psi short.
    No, Hilltop does not meet the minimum. 20 psi − 13 psi = 7 psi short of the 20 psi minimum.

  4. Answer: 43 psi.
    13 psi + 30 psi from the pump = 43 psi.

  5. Answer: Yes.
    43 psi falls inside the 40 to 80 psi service range.

  6. Answer: 231%.
    The rise is 43 − 13 = 30 psi. 30 ÷ 13 = 2.31, which is about a 231 percent increase.

  7. Answer: 49 psi.
    The water surface is 10 feet above Ridge Court. 10 × 0.433 = 4.33, about 4 psi. With the pump: 4.33 + 45 = 49.33, about 49 psi, which lands inside the 40 to 80 psi range.

  8. Answer: 52 psi.
    120 feet × 0.433 = 51.96, which rounds to 52 psi.

  9. Answer: High homes have little water height above them.
    Accept any answer explaining that pressure depends on how much water height sits above a point. High neighborhoods have little water above them, so their pressure is low and a pump is needed. The valley home has a tall column of water above it, so it already has strong pressure.

Differentiation

Support

Give students the conversion as a labeled rule, "feet of water above a point × 0.433 = psi," on a printed strip. Work item 1 together as a model, then let students try the rest. Allow a calculator throughout.

Extension

Ask students to find the greatest height, in feet, a neighborhood could sit above Main Street and still reach the service range after the pump adds a 30 psi boost. Have them show the reasoning behind their answer.

ELL supports

Provide a labeled diagram of the tower and three homes at different heights, with the water surface marked. Pre-teach "pressure," "booster pump," and "psi." Allow item 9 to be answered with a sentence frame: "High homes have ___ water above them, so their pressure is ___."