Answer:
If the particle is an electron 
If the particle is a proton, 
Explanation:
Initial speed at the origin, 
to +ve x-axis
The particle crosses the x-axis at , x = 1.5 cm = 0.015 m
The particle can either be an electron or a proton:
Mass of an electron, 
Mass of a proton, 
The electric field intensity along the positive y axis
, can be given by the formula:

If the particle is an electron:



If the particle is a proton:


