2017 USA Physics Olympiad Exam Part B 10 d.The proton beam enters the electromagnet and is deflected by an angle 6=10.Determine the magnetic field strength. Electromagnet Proton beam path e.The electromagnet is composed of layers of spiral wound copper pipe;the pipe has inner diameter di=0.40 cm and outer diameter do=0.50 cm.The copper pipe is wound into this flat spiral that has an inner diameter Di=20 cm and outer diameter Do=50 cm.Assuming the pipe almost touches in the spiral winding,determine the length L in one spiral. Do Di f.Hollow pipe is used instead of solid conductors in order to allow for cooling of the magnet. If the resistivity of copper is p=1.7 x 10-80.m,determine the electrical resistance of one spiral. g.There are N =24 coils stacked on top of each other.Tap water with an initial temperature of Te=18 C enters the spiral through the copper pipe to keep it from over heating;the water exits at a temperature of Th=31C.The copper pipe carries a direct 45 Amp current in order to generate the necessary magnetic field.At what rate must the cooling water flow be provided to the electromagnet?Express your answer in liters per second with only one significant digit.The specific heat capacity of water is 4200 J/C.kg;the density of water is 1000kg/m3. h.The protons are fired at a target consisting of Fluorine atoms(Z=9).What is the distance of closest approach to the center of the Fluorine nuclei for the protons?You can assume that the Fluorine does not move. Copyright C2017 American Association of Physics Teachers2017 USA Physics Olympiad Exam Part B 10 d. The proton beam enters the electromagnet and is deflected by an angle θ = 10◦ . Determine the magnetic field strength. θ Electromagnet Proton beam path e. The electromagnet is composed of layers of spiral wound copper pipe; the pipe has inner diameter di = 0.40 cm and outer diameter do = 0.50 cm. The copper pipe is wound into this flat spiral that has an inner diameter Di = 20 cm and outer diameter Do = 50 cm. Assuming the pipe almost touches in the spiral winding, determine the length L in one spiral. Di Do f. Hollow pipe is used instead of solid conductors in order to allow for cooling of the magnet. If the resistivity of copper is ρ = 1.7 × 10−8Ω · m, determine the electrical resistance of one spiral. g. There are N = 24 coils stacked on top of each other. Tap water with an initial temperature of Tc = 18◦ C enters the spiral through the copper pipe to keep it from over heating; the water exits at a temperature of Th = 31◦ C. The copper pipe carries a direct 45 Amp current in order to generate the necessary magnetic field. At what rate must the cooling water flow be provided to the electromagnet? Express your answer in liters per second with only one significant digit. The specific heat capacity of water is 4200 J/ ◦C · kg; the density of water is 1000 kg/m3 . h. The protons are fired at a target consisting of Fluorine atoms (Z = 9). What is the distance of closest approach to the center of the Fluorine nuclei for the protons? You can assume that the Fluorine does not move. Copyright c 2017 American Association of Physics Teachers