Final answer:
The electric field at point P can be calculated using the formula E = k * q / r^2, where k is the electrostatic constant, q is the charge, and r is the distance between the charge and point P.
Step-by-step explanation:
The electric field at point P can be calculated by considering the two charges individually and then adding their electric fields together. In this case, the charges are located on the z-axis. With the given information, we can use the formula for the electric field due to a point charge:
E = k * q / r^2
Where E is the electric field, k is the electrostatic constant (9 * 10^9 N m^2 / C^2), q is the charge, and r is the distance between the charge and the point P on the z-axis. By plugging in the values for each charge, we can calculate the electric field at point P in newtons per coulomb.