Answer:
a)
is the speed of each proton
b) 
Explanation:
Given:
radius of path of motion, 
we know charge on protons, 
magnetic field strength, 
we've mass of proton, 
a)
From the equivalence of magnetic force and the centripetal force on the proton:



where:
v = speed of the proton

is the speed of each proton
b)
Now the centripetal force on each proton:



<span>Every effect. Velocity is d/t distancee over time. Increase t velocity (Speed) decreases. Increase d velocity increases.</span>
<span>Yes, the vast majority of an atom is indeed empty space. Most of it's mass is centered in the nucleus. Flying around the nucleus are the electrons, but they're very very far away (on an atomic level anyway). Most of the atom is the space between the nucleus and the electrons.</span>
The work done by the electric field in moving a charge is the negative of the potential energy difference between the two locations, which is the product between the magnitude of the charge q and the potential difference

:

The proton charge is

, and the two locations have potential of

and

, therefore the work is