question A proton (mass 1.67 x 10 kg) is travelling with 3 = 1.29 x 10i ms- in an electric field E - 3.02 x 105j Vm 1. What is the smallest magnitude B of magnetic field required to keep it travelling in a straight line. Neglect all other forces in comparison with electric and magnetic. B = 0.234 T Your last answer was interpreted as follows: 0.234 Part 2) What is the direction of that magnetic field? k Part 3) A proton is travelling at constant speed in a circle in the , y plane with radius r = 13.3 mm. It completes one circle in a time 2.07/ s. The only non-negligible force acting on it is due to a uniform magnetic field B. Calculate the magnitude of Bz, the z component of the magnetic field acting on it. B2 = 5.04E-3 T Your last answer was interpreted as follows: 5.04e - 3