HOW PHYSICS HELPS US UNDERSTAND THE COSMOS

Activity 1 -The Twin Paradox Directions: Solve the problem to answer the question. Show all the Solutions. Consider a pair of brothers, identical twins Jessie and James. James gets a job as an astronaut and leaves Earth for a space voyage while Jessie decides to stay home. James rockets to the stars at a high speed of 90% the speed of light. According to Jessie's time, his twin brother's voyage took 40 years. Using the principle of Einstein's theory of relativity, the traveling twin should return younger than his brother. How old would James be upon his return to Earth? Activity 2 - How Far? How Powerful? Directions: Prove the inverse square relationship between distance and light intensity by following the procedures of the experiment at home. Procedures: 1. Gatherthe following materials at home. -scissors -tape measure -tapa 'single-hole hole punch -dark orange or dark red paper (at least? by 7cm) -flashlight -graphing calculator or computer to perform a power regression 2. Find a blank, flat wall to shine a light onto and a table or chair that can stabilize the flashlight for this lab. If you have a blank wall near the end of a lab table, then put the light on top of the table. You will need to be able to move the light (whether along the table or by moving the chair) at least 1 meter closer to or away from the wall. 3. Use the hole punch to punch a hole in the center of the dark orange or red paper. 4. Tape the paper to the light and of the ashlight, making sure the hole is roughly centered over the light. 5. Place the ashlight on the chair or table at least to cm from the wall. You can adjust it with papers or books so that it is level (i.e., the light beam shines perpendicular on the wall). Measure the distance from the wall to the hole on the front of the flashlight. Record this distance in your data table. 6. Turn the flashlight on. You should see a distinct white circle projected on the wall. The rest of the light emitted outside of this light should be a shade of the colored paper teed to the flashll-ht. Illustration of the lab set-up. (Credit: NASAIImagine the Universe) 7. Take 3 different measurements of the diameter of the circle of white light on the wall. HINT: Remember, the diameter of a circle is the longest measured chord from one edge of the circle to the other. Therefore, you know you've got the diameter when you hold one end of the tape measure on one side (edge) of the circle and get the largest measured value by moving the other end of the tape measure along the other side. 8. Record these values in the data chart. Calculate the mean and record it as well. 9. Move the chair with the flashlight (or move along the table} about 20 cm further away from the wall. Measure the distance from the wall to the hole on the front of the flashlight. Record this distance on your data table. 10. Repeat steps 6-8 at least two more times. 11.Calculate the radius from each mean diameter. Record each calculation in the data table. 12. Calculate the area of the circle formed from each calculated radius. Record each calculation in the data table. HINT: Area of a circle equals 11 r'. 13. In your graphics calculator, enter the distance from the hole to the wall as one list and the area of each calculated circle as another list. 14. Plot the data in the lists as a scatter plot. What kind of relationship do you see? 15. Calculate a Power Regression equation on the two lists. What is the equation? Activity 3 - Test Your Analysis Directions: In the table below, write a summary on how to solve speeds and distances of far-oil objects (First column) and give your brief explanation In the second column. Methcdfi'echnique in solving fer-off ExplanationIEquatlon ob ects' distances Methcdfl'echnlque in solving speed of tar- Explsnstlcnquuatlon off ob cts Reflection: 1.What were some of the most interesting discoveries I made while working on the different activities provided in the learning activity sheets for the whole second quarter? 2. What were some of my most challenging questions I encountered and what made them so? 3. What other Essential lessons did I learned. and how will I use them in my daily life