49. There is a uniform magnetic field of 0.50 T directed along the positive y-axis. (A) Determine the force exerted on a 4.0-A current in a 3.0-m long wire heading along the negative z-axis. (B) Determine the force on a 200-µC charge moving 60 km/s at an angle of 30° below the +x-axis. (C) In which direction(s) could a proton travel and experience zero magnetic force?

8. A charged particle moves in a horizontal plane with a speed of 8 70 106 . × m / s. When this particleencounters a uniform magnetic field in the vertical direction it begins to move on a circular path of radius15.9 cm. (a) If the magnitude of the magnetic field is 1.21 T, what is the charge-to-mass ratio (q/m) ofthis particle?

1. An electron moves west at 6.9 x 105 m/s through a magnetic field directed [W75°N] with strength of 1.3 x 102 T. What magnitude and direction would the electron experience a magnetic force?

9. A electron with charge -1.60 × 10-19 C and mass 9.11 × 10-31 kg is accelerated from rest through 14.20 kV. It then enters a uniform magnetic field of 7.50 x 10-4 T that is oriented perpendicular to its direction of motion. (a) What is the radius of the path the electron follows in the magnetic field? (b) How long does it take the electron to make one complete circle in the magnetic field?