MEASURING LENGTH IN METRICS

Transcription

1 MEASURING LENGTH IN METRICS Introduction GENERAL SCIENCE / EASY LEVEL Most science experiments are conducted using measurements in the metric system. Most countries use the metric system; therefore, scientists from different countries are able to understand and interpret data measured in metric units. In this activity, you will familiarize yourself with the meter, the metric unit for length, as well as related units like centimeters and millimeters. Time Needed 30 minutes What You Need string, about 6 feet (6 ft; about 1.83 meters) meterstick ruler with metric measurements sheet of lined paper to record measurements pencil Safety Precautions

2 What You Do 1. Take off your shoe from one foot, and with the ruler measure the length of your foot (heel to big toe) in centimeters. Record your measurement on the lined paper. 2. Using the ruler, measure the width of the nail on your little finger in millimeters. Record your measurement. 3. Wrap the string around your head once, as shown in Figure 1. string Figure 1 4. Keeping your finger on the string where it meets the end, use the ruler to measure the circumference of your head in centimeters. Record the measurement. 5. Hold one end of the string in one hand. Hold onto the string with your other hand and stretch it across your chest, as shown in Figure 2. string Figure 2

3 6. Measure your wingspan using the meterstick by measuring the length of the string you held across your chest with your arms outstretched. 7. Measure the length of the bottom of your shoe in centimeters using the ruler. Record the measurement. 8. Using the meterstick, measure the length of the room in meters. Record your measurement. Observations 1. Which is more practical to use for measuring the width of your hand the ruler or the meterstick? 2. What unit would you use to measure the length of your big toe? 3. What unit would you use to measure the length of a table? Metric Conversions for Length Metric System English System 1 millimeter (mm) in. 1 centimeter (cm) 10mm in. 1 meter (m) 100 cm yd 1 kilometer (km) 1000 m mile English System Metric System 1 inch (in.) 2.54 cm 1 foot (ft) 12 in m 1 yard (yd) 3 ft m 1 mile 1760 yd km

4 GENERAL 1.0 SAFETY GUIDELINES Always get your teacher s permission for experiments performed at school, and your parent s permission for experiments performed at home, before attempting any experiment. Read all instructions for an experiment several times before starting the experiment, and follow the directions exactly as they appear in this volume. If an experiment requires adult supervision, do not perform the experiment unless you have an adult supervising you the entire time you are performing the experiment. Wash your hands before the start of, and after, each experiment you perform. Keep your work area clean. Never eat or drink while performing a lab experiment. Never taste a substance used in an experiment unless you are told that it is safe to do so. Be aware of the location of equipment that you may need in an emergency, such as running water, an eyewash if you are at school, a fire extinguisher, etc. If you are going outside, make sure you have teacher or parent permission to go. Take a buddy with you and dress appropriately for the weather. Make sure you or someone who accompanies you is familiar with the area, and bring along a first-aid kit in case of an emergency. Never look directly into the Sun. CHEMICAL SAFETY Always wear goggles when working with chemicals, such as acids and bases, and near heat sources like flames. If at all possible, avoid wearing contact lenses when working with chemicals. If any substance gets into your eyes, notify an adult (e.g., your teacher or parent) immediately and flush your eyes with running water for at least 15 or more minutes. Do not mix chemicals unless you are told to do so by a teacher or parent. Never touch, taste, or smell chemicals unless instructed to do so. Keep chemicals in closed containers when they are not in use.

5 Dispose of all used chemicals properly. Do not pour any chemicals or solids down the drain unless instructed to do so. Use safety gloves and a plastic apron when handling chemicals. If any chemicals spill on your skin, rinse it with running water for at least 10 minutes, and notify your teacher or parent immediately. Take precautions to avoid spilling chemicals. If a chemical spills on any surface, notify your teacher or parent immediately to assist with clean-up. Exercise caution when using sharp instruments such as knives or scissors. Always cut away from yourself, not toward yourself. If you are cut, notify your teacher or parent immediately. GLASSWARE Clean glassware when you are finished with the experiment. Be careful when using glassware. If a piece of glassware breaks, have an adult assist you in clean-up to avoid injuries due to broken glass. Never use broken or damaged glassware. FIRE SAFETY Do not heat glassware that is not completely dry. Do not pick up hot glassware without heat-resistant gloves or tongs. When heating glassware, keep it away from yourself and from others. Do not heat anything unless instructed to do so by a teacher or parent. Do not heat substances in a closed container. After an experiment, make sure that all heating sources are turned off and that all flames have been put out. Do not reach across such heating sources as flames. Tie back long hair. Do not wear clothing with loose sleeves, scarves, bows, ties, or anything else that may hang into a fire. Do not wear long earrings. ELECTRICAL SAFETY Do not touch electrical equipment if your hands are wet. Do not plug many electrical devices into one outlet or use an extension cord.