In: Physics
A particle (mass = 6.7 x 10-27 kg, charge = 3.2 x 10-19 C) moves along the positive x axis with a speed of 4.1 x 105 m/s. It enters a region of uniform electric field parallel to its motion and comes to rest after moving 5.0 m into the field. What is the magnitude of the electric field (in N/C) ?
Mass of the particle 
Charge of the particle 
Initial speed of the particle 
Finally the particle comes to rest, final velocity of the
particle is 
Let E be the electric field, the force on the particle is F=qE
Work done by the electric field in displacing the particle by amount d=5.0m is

By work-energy theorem, the net work done on a particle is equal to the change in kinetic energy of the particle


Using 


The magnitude of the electric field is

Substituting values

