Answer:
Mass of ion will be
Explanation:
We have given ion is triply charged that is 
Radius r = 36 cm = 0.36 m
Velocity of the electron 
Magnetic field B = 0.55 T
We know that radius of the path is given by 

Choice - B is the correct one.
At the top of the arc, at one end of the swing:
-- it's not going to get any higher, so the potential energy is maximum
-- it stops moving for an instant, so the kinetic energy is zero
At the bottom of the arc, in the center of the swing:
-- it's not going to get any lower, so the potential energy is minimum
-- it's not going to move any faster, so the kinetic energy is maximum
Mass movement is the movement of surface materials caused by gravity. A great example would be a mud slide.