Physical Science 8th grade (1).pdf

# Whether it be research on a runners bones or a

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Whether it be research on a runner’s bones or a turkey’s, the scientific method is the foundation. Now you know there is more to your athletic shoe than just good looks. Questions: 1. What is the first step in the scientific method? 2. What are the main qualities of a good hypothesis? 3. What general hypothesis did scientists make about running shoes? 4. How do scientists and engineers test running shoes in the lab? Chapter 1 Connection

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24 Make a Water Clock A clock is a tool used to measure time. Inside a clock are parts that move with a constant repetition. We can record a quantity of time by counting how many “movements” of our clock occur during an interval of time that has a beginning and an end. The number of movements gives us our time measurement. In this activity, you and a partner will make your own clock and measure time with it. Materials Two empty 2-liter soda bottles 400 mL beaker Water Duct tape Stopwatch Making your clock 1. Put three beakers of water (1200 mL) into one of the empty soda bottles. 2. Attach the mouths of the two soda bottles together and seal them with duct tape. 3. Turn the two attached soda bottles upside down so that the water runs from one soda bottle to the other. 4. Seal your bottles with more duct tape if you have any leaks. Measuring time with your clock 5. One partner should hold the stopwatch, while the other partner holds the soda bottle clock. 6. One partner turns the soda bottle clock upside down at the same time the other partner starts the stopwatch. 7. Stop the stopwatch as soon as all the water has emptied from the top bottle to the bottom bottle. Record your data in the table. 8. Repeat the procedure two more times, and record your data in the table. 9. Switch roles and repeat the activity three more times. Record your data in the table. Discussion Questions a. Clocks are described as tools that measure time using moving parts. What is the moving part of your soda bottle clock? b. The new unit of time you created was the time it took the water to run from one bottle completely into the other. Give this unit of time a name. c. Using the data from your six trials, find the average number of seconds in your new unit of time and record it in the table. d. Maurice Green can run 100 meters in about 9.8 seconds. How many of your new units did it take? e. What are some problems with the clock you made today? Why isn’t this type of design used in many of our current clocks? Trial Time (seconds) 1 2 3 4 5 6 Average Chapter 1 Activity