PHY 2049 Midterm: University of Florida PHY 2049 exam1_sol_s07
Document Summary
Final exam solutions (first answer is correct: (exam 1) charges +9q and 3q are held in place at positions x = 0 m and x = 2 m, respec- tively. At what position in x (in m) should a third charge be placed so that it is in equilibrium? (1) +4. 73 (2) 2. 73 (3) +1. 27 (4) +0. 67 (5) 1. 86. We see immediately that the equilibrium point should be to the right of the 3q charge, i. e. x : put a charge q3 at position x. If l is the distance between the first two charges, then the total force on the third charge at equilibrium is xf. 0 yields x = +4. 73 m: (exam 1) a proton and an alpha particle (2 protons and 2 neutrons) are fixed in position 4. 5 cm apart. Another proton is shot from infinity and stops midway between the two.
