物理电磁问题
a proton moves with a speed of 2.5*10^6 m/s horizontally, at a right angle to a magnetic field. What magnetic field is required to just balance the weight of the proton and keep it moving horizontally?
Please show working.
参考答案:we Know a proton'charge e=1.610*10^-19 C
a proton'quality M = 1.673*10^-27 Kg
so Lorentz force F=QVB=eVB weight of the proton G=Mg
and it is equal to weight of the proton to Keep proton moving horizontally.
so F=Mg eVB=Mg B=Mg/eV=1.673*10^-27 Kg*9.8m/s^2/1.610*10^-19 C*2.5*10^6 m/s =4.07*10-14