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Investigation 1 / Motion of a Projectile Activity for Module 4: Investigation of the effect the angle and the initial velocity has on the height of the projectile and the distance it travels. 1. Go to the website: http://www.phys.virginia.edu/classes/109N/more_stuff/Applets/ProjectileMotion/jarapplet.h tml 2. Explore the features of the simulation window. You can choose to include air resistance and show trails by checking the appropriate boxes. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. You can change the initial velocity of the projectile, the angle at which it is launched and its mass by either sliding the scales or typing the value in the box. The values can be read in the center boxes. To launch the projectile, click the “fire” button. After firing: The top right hand corner displays the maximum distance and height of the projectile. It also states the final velocity and the total time the projectile is in the air. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. The path of the projectile is shown by colored dots when the “show trails” option is chosen. To clear the trails click the “refresh” or “reload” button for the browser. Set-up the simulation as follows: Check the box titled "Show Trails". Do not check the box titled "Air Resistance" (we will investigate this affect on projectile motion later.) In the velocity box type in an initial velocity of 50 m/s. In the angle box type in 45 degrees. In the mass box type in 1 kilogram. Part A: What is the effect of mass on the motion of a projectile? 1. Press the "fire" button to launch your first projectile. 2. Describe the shape of the path the projectile traces onto the screen. 3. At the top of the screen, read and record the projectile's statistics in the table below. Vi= 50 m/s Angle = 45° Mass of the Maximum Projectile Range (distance) (kilograms) (meters) 1 Maximum Elevation (height) (meters) End Velocity Total Time (m/s) (s) 5 10 20 4. Investigate the effect of mass on the projectile motion by typing in the masses shown in the table above. Do not change any other variables. 5. What affect does mass have on the motion characteristics listed in the table above? 6. Do you think the force applied to the different masses would also be the same? Explain your answer using Newton's Laws of Motion. 7. What amount of time do you estimate for the projectile to reach its Maximum Elevation? Part B: What is the effect of Initial Velocity on the motion of a projectile? 1. Refresh the web page and set these variables: Mass = 5 kg and Angle = 45° 2. Change the velocity to the values listed below and fill in the table. Initial Velocity (m/s) 10 Maximum Range (distance) (meters) Maximum Elevation (height) (meters) End Velocity Total Time (m/s) (s) 20 30 40 50 3. When the velocity was increased which of the data table measurements of the projectile motion also increased? 4. How does the initial velocity and end velocity of the projectile compare for each launch? 5. Describe the shape of all the projectile path's in this part of the lab? Part C: What is the effect of Launch Angle on the motion of a projectile? 1. Refresh the web page and set these variables: Mass = 5 kg and Initial Velocity = 50 m/s 2. Change the launch angle to the values listed below and fill in the table. Launch Angle (°) 10 Maximum Range (distance) (meters) Maximum Elevation (height) (meters) End Velocity Total Time (m/s) (s) 30 40 45 50 60 80 90 3. At what angle was the maximum range (horizontal distance) reached? 4. At what angle was the maximum elevation achieved? 5. At what angle was the greatest "hang" time achieved? 6. Compare the maximum range (horizontal distance) reached for these pairs of launch angles. 10° = __________ meters and 80° = __________ meters 30° = __________ meters and 60° = __________ meters What pattern is observed for these angles and their maximum ranges? What is the sum of these paired angles? What are some other paired combinations in the data table that share the same maximum range? 7. A projectile is launched at an initial speed of 50 m/s with a horizontal angle of 76°. Use the simulation to answer these questions: What is its range? State another angle that will produce the same range. Does the simulation verify your prediction? What is the sum of the two angles that produce this range? Part D: What is the effect of air resistance on the motion of a projectile? 1. Refresh the web page and set the Mass = 5 kg. 2. Change the Air Resistance, Initial Velocity and Angle to the values listed below and fill in the table. Air Resistance Initial Velocity Angle yes (m/s) 30 (°) 35 no 30 35 yes 30 65 no 30 65 yes 60 35 no 60 35 yes 60 65 no 60 65 yes 60 90 no 60 90 Maximum Range (distance) (m) Maximum Elevation (height) (m) End Velocity Time (m/s) (s) 3. How does air resistance affect the following characteristics of projectile motion: a) Maximum Range: b) Maximum Height: c) Total Time ("hang time"): d) End Velocity: Part E: Summary In your own words, state the major concepts you learned about from this simulation. This is the only section that you need to e-mail to me. However, you may want to compare your detailed findings with your “homework buddy.”