Natural Science Physics free essay sample

This seems to go in a linear pattern however not enough information to determine why the sudden drop after the peak. 2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water. If the added dissolved oxygen in water is increased then the greater the number of fish will be observed. 3. What would your experimental approach be to test this hypothesis? My experimental approach would be is to have dissolved oxygen water at hand pouring after a certain amount and time to observe the fish that is gathering at a certain area in the water. Recording my observation in a controlled environment is the key with the safety in mind. 4. What are the independent and dependent variables? The independent variable is the dissolved oxygen water and the dependent variable is the amount of fish that appears. We will write a custom essay sample on Natural Science Physics or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 5. What would be your control? Water absent of dissolved oxygen, temperature, humidity, the current if plausible. 6. What type of graph would be appropriate for this data set? Why? A line graph is the appropriate data set to show the increases and decreases of observed fish to appear at a certain level of dissolved oxygen water. . Graph the data from Table 1: Water Quality vs. Fish Population (found at the beginning of this exercise). You may use Excel, then â€Å"Insert† the graph, or use another drawing program. You may also draw it neatly by hand and scan your drawing. If you choose this option, you must insert the scanned jpg image here. 8. Interpret the data from the graph made in Question 7. As you add increments of dissolved oxygen water the population of fish increases. However, once it reaches a certain peak the population dips then returns back up. It is uncertain why this happened but all I can say is that I need more information of whether the change was influenced by other variables and will the population of fish stay constant if the added dissolved water increases further on. Exercise 2: Testable Observations Determine which of the following observations (A-J) could lead to a testable hypothesis. For those that are testable: Write a hypothesis and null hypothesis What would be your experimental approach? What are the dependent and independent variables? What is your control? How will you collect your data? How will you present your data (charts, graphs, types)? How will you analyze your data? 1. When a plant is placed on a window sill, it grows three inches faster per day than when it is placed on a coffee table in the middle of the living room. Testable Hypothesis: If I place the plant on the window sill and not on the coffee table located in the middle of the living than my plant will grow 3 inches faster per day. Null hypothesis: If I place my plant on the window sill and not on the coffee table located in the middle of the living room than my plant will not grow as fast per day. What would be your experimental approach? I would have two plants to compare one on the window sill and one on the coffee table in the middle of the room. I would collect measurements in centimeters with a ruler and record my findings every day for three weeks. What are the dependent and independent variables? Independent variable is the plant on the window sill. Dependent variable is how fast the plant grows. What is your control? The control is the regular plants outside the garden. How will you collect your data? Every day for three weeks I will record the growth in cm and comprise a table after three weeks. Then I would make a line graph to compare the plants growth speed. Record any physical findings that might alter my experiment. How will you present your data (charts, graphs, types)? I will present my finding on a line graph labeled for two plants showing the difference throughout the days in the three weeks. How will you analyze your data? I would analyze my data by proving that my hypothesis was right that the plant will grow faster on the window sill compared to the coffee table. Then point out other factors that could influence the plants growth for having a dirty window would block most of the sun’s rays, the amount of water it needs during the day, the soil that needs tending for it to grow, or other plant characteristic to help it to grow. Sometimes researching beforehand would be the best bet to ensure its growth. 2. The teller at the bank with brown hair and brown eyes and is taller than the other tellers. Not Testable 3. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats unhealthy foods. Testable Hypothesis: Eating healthy food and exercising regularly, lowers Sally’s blood pressure by 10 points than not exercising and eating unhealthy food. Null hypothesis: Eating unhealthy food and not exercising will lower Sally’s blood pressure by 10 points than eating healthy food and exercising regularly. What would be your experimental approach? The experimental approach is to make Sally eat healthy food and exercise regularly for three weeks and check her blood pressure and heart rate for the next 15 days. While comparing her previous BPs’ before she decided to change her life style. What are the dependent and independent variables? Independent variable: Sally bringing down her Blood pressure. Dependent variable: eating unhealthy food without exercise brings bp up by 10 points. What is your control? Control is the amount Sally eats per week and the amount of hours spent in the gym exercising. How will you collect your data? Sally keeps a journal of her daily diet and exercise for 3 weeks and comes in for blood pressure checkups every day for the next few weeks. I would compare the diastolic and systolic pressures to the past results before she changed her life style. How will you present your data (charts, graphs, types)? The data will be presented in a line chart showing the systolic and diastolic results. How will you analyze your data? I will analyze the data and observe the numbers and ask Sally questions that might be stressors in her life that might change her results. 4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm. Not testable 5. For the past two days the clouds have come out at 3 pm and it has started raining at 3:15 pm. Not Testable 6. George did not sleep at all the night following the start of daylight savings. Not testable ? Exercise 3: Conversion For each of the following, convert each value into the designated units. 1. 46,756,790 mg = _46. 75679_____ kg 2. 5. 6 hours = ___20160_____ seconds 3. 13. 5 cm = ___5. 31_____ inches 4. 47  °C = ___116. 6____  °F Exercise 4: Accuracy and Precision 1. During gym class, four students decided to see if they could beat the norm of 45 sit-ups in a minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67. 2. The average score for the 5th grade math test is 89. 5. The top 4th graders took the test and scored 89, 93, 91 and 87. The four students who beat 45 sit-ups in one minute relates to accuracy. For the average score for the 5th grade math class compared to the 4th grade top students is an example of precision due to the close averages. 2. Yesterday the temperature was 89  °F, tomorrow it’s supposed to be 88 °F and the next day it’s supposed to be 90 °F, even though the average for September is only 75 °F degrees! Accuracy 3. ? Four friends decided to go out and play horseshoes. They took a picture of their results shown to the right: Precision 4. A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005 and 689. The grocery clerk said the jar actually contains 568 pennies. Accuracy Exercise 5: Significant Digits and Scientific Notation Part 1: Determine the number of significant digits in each number and write out the specific significant digits. 1. 405000= 3 sig dig= 4. 05*10^5 2. . 0098= 2 sig dig=9. 8*10^-3 3. 39. 999999= 8 sig dig= 3. 9999999*10^1 4. 13. 00= 4 sig dig= 1. 3*10^1 5. 80,000,089= 8 sig dig= 8. 0000089*10^7 6. 55,430. 00= 7 sig dig= 5. 543*10^4 7. 0. 000033= 2 sig dig= 3. 3*10^-5 8. 620. 03080= 7 sig dig=6. 200308*10^2 Part 2: Write the numbers below in scientific notation, incorporating what you know about significant digits. 1. 70,000,000,000= 7. 0*10^10 2. 0. 000000048= 4. 8*10^-8 3. 67,890,000= 6. 789*10^7 4. 70,500= 7. 05*10^4 5. 450,900,800= 4. 509008*10^8 6. 0. 009045= 9. 045*10^-3 7. 0. 023=2. 3*10^-2