What explains the result?
Water moves through narrow spaces between towel fibers by capillary action, with gravity and wetting also involved.
PHYSICAL SCIENCE · GRADES 4–8
Walking water bridge
INVESTIGATION QUESTIONHow does paper towel type change the time water takes to reach the next cup?
● ILLUSTRATIVE SCIENCE MODEL
ENGLISH CAPTIONS
Set up matched cup pairs. Each pair will compare one paper towel type under matched conditions.
0.0 / 3.0 s
Where does this matter?
Capillary movement helps explain water traveling through paper and plant tissues.
What should you keep in mind?
Illustrative times are not guaranteed results. Towel weave, strip dimensions, starting level, cup spacing, and timing affect the result; compare repeated real trials.
DEDICATED PAPER-TOWEL COMPARISON · GRADES 2–6
Make the water
walk
Test one towel type per matched cup pair. Observe the capillary bridge, then record the real time until colored water first reaches the empty cup.
SAMPLE A · THIN, LOW-COSTDRY SETUP
SOURCE 1
EMPTY CUP
SOURCE 2
EMPTY CUP
SOURCE 3
FOLD EACH STRIP INTO AN INVERTED V
ILLUSTRATED CHECK0/5
SetupMinutesHoursOvernight
OBSERVATION JOURNAL
Compare actual arrival times
The model never invents a real arrival time. Use the field above to record what your actual cup setup shows.
WHY IT MOVES: Water adheres to cellulose fibers and cohesion pulls neighboring water molecules along. Tiny spaces support capillary movement upward; after the fold, gravity helps it flow down. Plants use related transport, but xylem is living tissue and has additional biological forces.