High school students can try making a timing device for science projects. These projects can build an understand for the need for time measurement and how to design a time keeping device. The students must match the device to a precise timing keeping clock. Students can make a timing device using some simple materials such as plastic cups, tin cans,.homemade hourglasses and water.
Empty Cans and Water
The students can take tin cans and fill the cans with water. Then make a small hole at the bottom of the tin can. Use a second container, such as a tin plate or jar to collect water. As water drips out of the hole in the can, students carefully count the drops and the time between drops. The students can repeat the experiment to tell the precise time. The purpose of the experiment is to demonstrate the accuracy of the timing device.
Simple Computer Based Timers
The students can choose computer and the LOGO computer language as the basis to construct a device. The LOGO language is an object oriented, simple programming language that was first introduced in the late 1970s. Logo is a programming language that is simple to understand, therefore easy for students to learn. While the initial attempts will likely be unreliable, students can eventually construct LOGO based clocks that are accurate and precise. Students can design the clock that includes all three hands on a traditional clock and thereby match the timekeeping ability of the LOGO clock to a standard classroom clock. The clocks can even be modified to include audio sounds, like a beep for the passage of every second or minute.
Timing Devices with Water
The students can also construct a timing device using inexpensive materials like plastic cups. Students would need to make a seesaw using the cups. Students put a small weight on one end of the seesaw and an empty cup on the other end. The students then have to devise a controlled method for water to flow into the cup on the seesaw. As water flows into the cup on a seesaw, after a period of time, the seesaw will tilt because of the new weight in the cup. Students then face the challenge of matching the time it takes for the seesaw to tilt to a fixed period of time. The time period can be adjusted by changing the water flow rate or changing the mass of the counterweight on the seesaw.
A device with practical applications for the world that high school students live in, students can make a timing device that sets a fixed time limit, and then use the timer to monitor the amount of time a person is allowed to talk on the phone. Students can use sand and a can. The students put a small hole in the can, which allows the sand to pour out of a clean aluminum can, which sits on a small lever. On one end of the lever is the can filled with sand. On the other is a small weight. Under the weighted end of the lever is the disconnect switch on a traditional desk phone. Students are allowed to make a call, and as the call begins, the sand begins to drain out of the can through a small hole. When enough sand drains out of the can, the lever tilts, and the weighted end falls onto the phone's disconnect switch, terminating the call.
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