A proton moving at a constant velocity of 10 x 10s ms enters

A proton moving at a constant velocity of 1.0 x 10^s m/s enters a relatively unexplored region of space. It continues to move at its initial velocity. Can we assume there at no electric fields and/or magnetic fields present in the vicinity? Explain your reasoning.

Solution

There is no elecric field and magnetic field present in the vicinity.So, there is no electric force or magnetic force on proton.i.e., force on proton is zero

We know force F = ma

From this accleration a = F / m      Where m = mass

                                  = 0 / m

                                  = 0

             (v-u) / t = 0    Where u = initial velocity , v = final velocity

                   v - u = 0

                        v = u

i.e., initial velocity u and final velocity is same.

Therefore its moves at its initial velocity