Question

In a mass spectrometer chlorine ions of mass 35u and charge +5e are emitted from a source and accelerated through a potential difference of 250 kV. They then enter a region with a magnetic field that is perpendicular to their original direction of motion. The chlorine ions exit the spectrometer after being bent along a path with radius of curvature 3.5 m. What is the speed of the chlorine ions as they enter the magnetic field region?

(u = 1.66 × 10^(–27) kg, e = 1.6 × 10^(–19) C)
2.6 × 106 m/s
1.2 × 106 m/s
1.5 × 107 m/s

Answer 1

v=26.23*105 m/s

or 2.6 × 106 m/s

Step-by-step explanation:

Force generated by magnetic field will only provide centripetal acceleration thus the entering speed will be same as the exit speed

so,

.5mv2=eV potential differnce*charge= kinetic energy

.5*35*1.66*10-27*v2= 1.6*10-19*5*250000

v2=68.84*1011

v=26.23*105 m/s

or 2.6 × 106 m/s