Lab / experiment Grade 8 Engineering & Design

Booster Pump Lift Height and Flow Rate: A Grade 8 Testing Lab

A grade 8 engineering lab where students test how lift height affects a hand pump's flow rate, then graph the results on a scatter plot and fit a trend line.

Grade: Grade 8
Subject: Engineering & Design
Material: Lab / experiment
Time: 50 min
Prep: Moderate prep
Materials: 60 mL plastic syringe (1 per group, used as a hand pump), 5 feet of flexible aquarium airline tubing (1 per group), Shallow plastic basin or tub filled with water (1 per group), 100 mL graduated cylinder (1 per group), Stopwatch or phone timer, Yardstick or tape measure, Sturdy stool, chair, or stacked boxes to create height platforms of 1, 2, and 3 feet, About 2 liters of water per group, Towels for spills

Standards

MS-ETS1-4 NGSS

Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

How this material aligns: Students run repeated pumping trials at four lift heights to generate the iterative test data this standard requires for understanding how a design variable affects performance.

All materials for MS-ETS1-4 →

8.SP.A.1 Common Core Math

Construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities, describing clustering, outliers, and positive, negative, linear, or nonlinear association.

How this material aligns: Students construct a scatter plot of lift height versus flow rate and describe whether the association is positive, negative, or roughly linear, exactly as this standard specifies.

All materials for 8.SP.A.1 →

8.SP.A.2 Common Core Math

Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line and assess the model fit by judging the closeness of the data points to the line.

How this material aligns: Students informally fit a trend line to their four data points and use it to predict a flow rate beyond their tested range, the model-fitting task this standard describes.

All materials for 8.SP.A.2 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-15.

Objectives

Students will measure how a pump's flow rate changes as the vertical lift height increases.
Students will construct a scatter plot of their data and describe the association between height and flow rate.
Students will calculate the additional pressure a pump must overcome at greater lift heights using a standard hydraulic conversion.

Teacher overview

Every pump that lifts water uphill, from a household well pump to the booster pumps that serve homes on a hillside, has to work harder as the lift height increases, because it must overcome more water pressure at greater heights. This lab has students pump a fixed volume of water to increasing heights using a simple hand pump, time each trial, and calculate a flow rate, then plot the results on a scatter plot to see the height-versus-flow-rate relationship directly in their own data. The real hydraulic conversion behind this pattern, that every foot of water height adds 0.433 psi of pressure, is the same figure licensed water operators use to size pumps for real distribution systems.

Booster Pump Lift Height and Flow Rate: A Grade 8 Testing Lab — Grade 8 Engineering & Design

Name: ____________________________ Date: ______________

Procedure

Step 1 (safety note): Use only clean tap water for this investigation, do not drink or taste any water used in the lab, and wipe up spills immediately to prevent slipping. Make sure any stacked boxes or stools used for height platforms are stable before pumping near them.

Step 2 (set up, 5 min): Set up your shallow basin of water on the table. Place your graduated cylinder at the same table height for Trial 1, so the lift height for this trial is 0 feet. Tape or clip one end of the tubing over the rim of the graduated cylinder so it points inside. Keep the syringe at table level beside the basin for every trial.

Step 3 (Trial 1, 0 feet, 5 min): Fill the syringe from the basin, push its tip into the free end of the tubing, and press the plunger to send water up the tube into the graduated cylinder. Pull the syringe off, refill it from the basin, reattach it, and repeat until the cylinder reads 100 mL. Start the stopwatch when you first fill the syringe and stop it when the cylinder reads 100 mL. Record the time in your data table.

Step 4 (Trial 2, 1 foot, 5 min): Raise the graduated cylinder to a height of 1 foot above the basin, using a stool, chair, or stacked boxes, and measure the height with the yardstick to confirm it. Repeat the 100 mL pumping trial and record the time.

Step 5 (Trials 3 and 4, 10 min): Repeat the same steps at lift heights of 2 feet and 3 feet, keeping your pumping speed and effort as consistent as possible across all four trials.

Step 6 (calculate, 10 min): Calculate the flow rate in milliliters per second for each trial using flow rate = 100 mL ÷ time in seconds.

Step 7 (graph, 10 min): Plot your four data points on a scatter plot with lift height (feet) on the horizontal axis and flow rate (mL/s) on the vertical axis. Draw an informal trend line through your four points that best represents the overall pattern in your data.

Data & Analysis

Trial	Lift height (ft)	Time to pump 100 mL (s)	Flow rate (mL/s)
1	0
2	1
3	2
4	3

What was your flow rate at 0 feet of lift? Show your calculation.
What was your flow rate at 3 feet of lift? Show your calculation.
Describe the association shown in your scatter plot between lift height and flow rate (positive, negative, or no clear association), and explain in your own words why this pattern makes sense for a pump.
Using the trend line you drew, predict the flow rate you would expect at a lift height of 4 feet if the pattern in your data continued.
Suppose your classroom pump were a real booster pump serving homes on a hillside. Using the real conversion that every foot of water height adds 0.433 psi of pressure, calculate how much additional pressure the pump must overcome lifting water 3 feet compared with lifting it 0 feet.
Based on your results, explain why a utility serving homes on a hill above its treatment plant or tank typically needs a stronger pump, or an additional booster pump, compared with a utility serving homes at the same elevation as its water source.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: varies by group's own data.
Should equal 100 mL divided by the group's recorded Trial 1 time. For example, a group whose Trial 1 took 10 seconds would report a flow rate of 10 mL/s.
Answer: varies by group's own data.
Should equal 100 mL divided by the group's recorded Trial 4 time, and should be a lower number than the Trial 1 flow rate if the pump behaved as expected. If a group's data does not show that pattern, discuss as a class how differences in pumping force from trial to trial can mask the underlying effect of height on flow rate.
Answer: A negative association.
As lift height increases, flow rate decreases, because the pump must do more work against gravity and pressure at greater heights, which leaves less pumping effort available to move water quickly through the tubing.
Answer: varies by group's own trend line.
Predictions should continue the downward pattern shown by the group's own trend line and should be a lower flow rate than the value recorded at 3 feet. Accept any value consistent with extending the line.
Answer: about 1.3 psi.
3 ft × 0.433 psi/ft = 1.299 psi, which rounds to about 1.3 psi. This is the additional pressure the pump must overcome at 3 feet of lift compared with 0 feet.
Answer: Homes on a hill sit above the level of the pump or tank, so the pump must overcome additional pressure, about 0.433 psi for every extra foot of elevation, beyond what it takes to serve homes at the same level as the source. To maintain adequate pressure at the tap, the utility typically needs a stronger pump or a separate booster pump for the higher elevation.

Differentiation

Support (below grade level)

Pre-mark the height platforms at 1, 2, and 3 feet before class so groups do not need to measure and stack them during the lab, and provide a printed conversion card stating "flow rate = 100 mL ÷ time in seconds" for reference during calculations.

Extension (above grade level)

Have groups test a fifth lift height beyond 3 feet, add that point to their scatter plot, and compare how closely the new point matches the prediction they made in analysis question 4, explaining any difference between the prediction and the actual result.

ELL supports

Provide a labeled diagram of the setup showing the basin, tubing, pump, and each height platform with its measurement marked in advance. Allow students to record their scatter plot description in analysis question 3 as a single word (positive, negative, or none) plus a labeled sketch of the pattern, rather than a full written explanation.