AP Physics B SUMMER ASSIGNMENT Summer, 2013 Instructor: Rhett Butler Welcome to AP Physics! I am delighted to be in the position to help further your understanding of the physical world around us. I also love the educational dynamics of the College Board’s Advanced Placement Program as it properly puts teacher and students on the “same side”. No longer is it “the teacher” vs. “the students”; it is “us” vs. “them” (The College Board). My primary objective for the year is to prepare you to destroy the AP exam in May. If you work hard on a consistent basis and follow my instructions, you will. As you already know, this course is more rigorous than CP Physics. It is relatively fast-paced and will require you to quickly master concepts and then apply mathematics to solve practical problems. At a minimum, you need a strong background in Algebra and be comfortable modeling, graphing and analyzing data and manipulating linear and quadratic equations. Being enrolled concurrently in either Honors Pre-Calculus or AP Calculus will help you to take full advantage of what the course has to offer. Completion of this summer assignment is obligatory for entering the course in August. To motivate you further, the summer assignment will count 10% towards your first quarter grade. Please be sure to pick up your copy of the textbook, Physics by Cutnell and Johnson, before you leave for the holidays. Contact information: Email: rhett.butler@asfg.edu.mx I will give you my home telephone number before the start of the summer vacation and you can call me anytime between the hours of 9 am to 9 pm, seven days a week. Purpose of this summer assignment: The purpose of this summer assignment is to help you review the concepts you learned during the past year so that we can quickly begin to work on new content when school starts in the fall. It should take approximately ten (10) hours to complete. Materials: 1. 2. 3. 4. 5. Physics reference material A spiral-bound notebook, 8 1/2” x 11”, graph-paper type Pencil, pen (blue or black), sharpener, eraser Scientific calculator (TI-89 or TI-Npire CX CAS) MacBook Pro 1 6. 7. 8. ASFG Google account Textbook: Physics, Cutnell & Johnson, 8th edition Online resources: a. The Physics Classroom b. The Khan Academy c. Others Summer Assignment Instructions: 1. Solve problems 1 – 8 on the following pages. Note that the due dates are staggered with approximately one problem being due each week (N.B. the first due date is Friday, June 21, 2013). Scan (or photograph) your solution to each problem and then upload each solution individually to your shared Google Folder (see Problem 0) by the given due date. Name your solution using the following format: apphysics.blow.joseph.summerassignment.problem1 2. Work independently. If you cannot solve a problem independently, contact a classmate. If you and your classmate(s) cannot solve a problem, conduct an Internet search for a hint (or solution). If all of the above strategies fail, call me. 3. Work neatly 4. Define variables clearly 5. Draw labeled diagrams, as needed 6. Be respectful of units 7. Solve one problem per sheet(s) of paper 8. Solve problems using variables; only substitute numerical values at the conclusion of a problem, if requested 9. Write a full sentence in your best English to summarize each of your answers 10. Think about physics in your everyday life 11. Have fun and be safe. 2 Problem 0: Due June 21, 2013 Create a Google folder for your summer assignment by following these steps: 1. Log into your ASFG Google account, select “Drive” on the menu at the top of the page, and then click “My Drive”. 2. Click the red “Create” button at the top left-hand side of the page and select “Folder” from the pull-down menu. 3. Enter the name of the folder using the following format EXACTLY, but substitute your data: apphysics.lastname.firstname.summerassignment Do not include any spaces. Here is an example folder name: apphysics.blow.joseph.summerassignment 4. Click “Create”. 5. Now hover your mouse over the file so that the little triangle becomes visible to the right of the file name. Click on it and select “Share” →”Share”. The “Sharing settings” dialog box will appear. 6. Click “Change” under “Who has access” 7. Change: “People at American School Foundation of Guadalajara who have the link can view” To “Private” 8. Click “Save” 9. Under “Add people:”, search for “ Rhett Butler” and add me to the dialog box. 10. Next, deselect the box “Notify people via email” and click the green “Share and save” button. 11. Click “Done”. Note: Problem 1 on the next page is also due on June 21, 2013 3 Problem 1: Due June 21, 2013 1994B1 (modified) A ball of mass 0.5 kilogram, initially at rest, is kicked directly toward a fence from a point 32 meters away, as shown above. The velocity of the ball as it leaves the kicker's foot is 20 meters per second at an angle of 37° above the horizontal. The top of the fence is 2.5 meters high. The ball hits nothing while in flight and air resistance is negligible. a. Determine the time it takes for the ball to reach the plane of the fence. b. Will the ball hit the fence? If so, how far below the top of the fence will it hit? If not, how far above the top of the fence will it pass? c. On the axes below, sketch the horizontal and vertical components of the velocity of the ball as functions of time until the ball reaches the plane of the fence. 4 5 Problem 2: Due June 28, 2013 2003Bb1 (modified) An airplane accelerates uniformly from rest. A physicist passenger holds up a thin string of negligible mass to which she has tied her ring, which has a mass m. She notices that as the plane accelerates down the runway, the string makes an angle with the vertical as shown above. a. In the space below, draw a free-body diagram of the ring, showing and labeling all the forces present. The plane reaches a takeoff speed of 65 m/s after accelerating for a total of 30 s. b. c. Determine the minimum length of the runway needed. Determine the angle θ that the string makes with the vertical during the acceleration of the plane before it leaves the ground. 6 Problem 3: Due July 5, 2013 1983B1. A box of uniform density weighing 100 newtons moves in a straight line with constant speed along a horizontal surface. The coefficient of sliding friction is 0.4 and a rope exerts a force F in the direction of motion as shown above. a. On the diagram below, draw and identify all the forces on the box. b. Calculate the force F exerted by the rope that keeps the box moving with constant speed. c. A horizontal force F', applied at a height 5/3 meters above the surface as shown in the diagram above, is just sufficient to cause the box to begin to tip forward about an axis through point P. The box is 1 meter wide and 2 meters high. Calculate the force F’. 7 Problem 4: Due July 12, 2013 1992B1. A 0.10-kilogram solid rubber ball is attached to the end of an 0.80 meter length of light thread. The ball is swung in a vertical circle, as shown in the diagram above. Point P, the lowest point of the circle, is 0.20 meter above the floor. The speed of the ball at the top of the circle is 6.0 meters per second, and the total energy of the ball is kept constant. a. Determine the total energy of the ball, using the floor as the zero point for gravitational potential energy. b. Determine the speed of the ball at point P, the lowest point of the circle. c. Determine the tension in the thread at i. the top of the circle; ii. the bottom of the circle. The ball only reaches the top of the circle once before the thread breaks when the ball is at the lowest point of the circle. d. Determine the horizontal distance that the ball travels before hitting the floor. 8 Problem 5: Due July 19, 2013 1978B2. A block of mass M1 travels horizontally with a constant speed vo on a plateau of height H until it comes to a cliff. A toboggan of mass M 2 is positioned on level ground below the cliff as shown above. The center of the toboggan is a distance D from the base of the cliff. (a) Determine D in terms of vo, H, and g so that the block lands in the center of the toboggan. (b) The block sticks to the toboggan which is free to slide without friction. Determine the resulting velocity of the block and toboggan. 9 Problem 6: Due July 26, 2013 *1977M3. Two stars each of mass M form a binary star system such that both stars move in the same circular orbit of radius R. The universal gravitational constant is G. a. Use Newton's laws of motion and gravitation to find an expression for the speed v of either star in terms of R, G, and M. b. Express the total energy E of the binary star system in terms of R, G, and M. c. Suppose instead, one of the stars had a mass 2M. On the following diagram, show circular orbits for this star system. 2M d. Find the ratio of the speeds, v2M/vM. 10 Problem 7: Due August 2, 2013 2005B2B A simple pendulum consists of a bob of mass 0.085 kg attached to a string of length 1.5 m. The pendulum is raised to point Q, which is 0.08 m above its lowest position, and released so that it oscillates with smallamplitude θ between the points P and Q as shown below. (a) On the figures below, draw free-body diagrams showing and labeling the forces acting on the bob in each of the situations described. i. When it is at point P ii. When it is in motion at its lowest position (b) Calculate the speed v of the bob at its lowest position. (c) Calculate the tension in the string when the bob is passing through its lowest position. (d) Describe one modification that could be made to double the period of oscillation. 11 Problem 8: August 9, 2013 B2007B4. A cylindrical tank containing water of density 1000 kg/m3 is filled to a height of 0.70 m and placed on a stand as shown in the cross section above. A hole of radius 0.0010 m in the bottom of the tank is opened. Water then flows through the hole and through an opening in the stand and is collected in a tray 0.30 m below the hole. At the same time, water is added to the tank at an appropriate rate so that the water level in the tank remains constant. (a) Calculate the speed at which the water flows out from the hole. (b) Calculate the volume rate at which water flows out from the hole. (c) Calculate the volume of water collected in the tray in t = 2.0 minutes. (d) Calculate the time it takes for a given droplet of water to fall 0.25 m from the hole. 12