College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 88

A long, straight wire lies on a horizontal table in the xy -plane and carries a current of 1.20 A in the positive x -direction along the x -axis. A proton is traveling in the negative x -direction at speed 2.30 × 10 4 m/s a distance d above the wire (i.e., z = d ). (a) What is the direction of the magnetic field of the wire at the position of the proton (b) What is the direction of the magnetic force acting on the proton (c) Explain why the direction of the proton's motion doesn't change. (d) Using Newton's second law, find a symbolic expression for d in terms of the acceleration of gravity g , the proton mass m , its speed v , charge q , and the current I. (e) Find the numeric answer for the distance d using the results of part (d).