I think you need to add more.. but I may know where you are leading 
Was he 200 m away and made the trip in 200 seconds?
If yes...
2 m/s was his speed and 0 velocity
        
             
        
        
        
Answer:
Magnetic field, B = 0.042 T
Explanation:
It is given that,
Speed of charged particle, 
Angle between velocity and the magnetic field, 
Charge, 
Magnetic force, F = 0.002 N
The magnetic force is given by :

B is the magnetic field   


B = 0.042 T
So, the strength of the magnetic field is 0.042 Tesla. Hence, this is the required solution.
 
        
             
        
        
        
Runoff because the mud is a liquid and moves on an amount of water that is in it like with quicksand