College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 67

Sodium ions (Na + ) move at 0.851 m/s through a bloodstream in the arm of a person standing near a large magnet. The magnetic field has a strength of 0.254 T and makes an angle of 51.0° with the motion of the sodium ions. The arm contains 100 cm 3 of blood with a concentration of 3.00 × 10 20 Na + ions per cubic centimeter. If no other ions were present in the arm, what would be the magnetic force on the arm