Estudiante

How to Make a Water Clock
Water clocks were among the first time-keeping devices. They were more precise than sun dials because they could measure the time in minutes rather than just in hours.They involved suspending one container above another. The first container dripped water in small, steady drops into the second container which was marked with minute-hour lines. Ancient people couldtell the time from where the water line was. Though later inventors discovered the water drips slowed as the level of the top container decreased, these clocks remained in use for some time. Studentscan learn about history and science by creating one of their own.

Materials:
Clear plastic water bottle
Needle
Thimble
Modeling clay
Graduated cylinder
Funnel
Water
Stopwatch
Painter's tapInstructions:
1) Rinse and wash clear plastic water bottle thoroughly, removing any traces of label adhesive. Flat-bottom bottles work best for this. Carefully poke a hole through the center ofthe bottom of the bottle with a needle; use a thimble to help avoid injury.

2) Roll a small ring of modeling clay the same size as the mouth of your graduated cylinder. Press the clay ring onto themouth of the cylinder. The cylinder should be wide and sturdy enough hold the water bottle upright without aid. The modeling clay is only a precaution.

3) Press the bottom of the bottle into themodeling clay ring, making sure the bottle is perfectly straight and the hole is centered. Slip a funnel into the mouth of the bottle, and carefully fill the bottle with water.

4) Start yourstopwatch, and see how much of the cylinder fills in a minute. Place little pieces of colored painter’s tape at 10-minute intervals. For instance, if 1 milliliter of water falls in a minute, place a pieceof tape every 10 milliliters.

Escuela Gran Comision

Mrs. Ninoska Funes

Group: Estefany Castro
Juan Diego Zarruk
Justin Amaya

Science Fair Experiment

8th Grade

February/1/2013