Answer:
The magnetic field is 1.16 T.
Explanation:
speed, v = 10% of speed of light = 3 x 10^7 m/s
diameter, d = 54 cm
radius, r = 0.27 m
charge, q = 1.6 x 10^-19 C
mass, m = 1.67 x 10^-27 kg
Let the magnetic field is B.
The centripetal force is balanced by the magnetic force.

Answer: 
The chromium nucleus will complete the reaction.
Explanation:
The given reaction is a type of radioactive nuclei decay:
Positron emission: It is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. This is also known as
-decay. In this the mass number remains same.

Now according to the given reaction:

The chromium nucleus will complete the reaction.
In order to describe motion along a straight line, you must state the speed and direction of the motion. Those two quantities, together, comprise what's known as "velocity".