Apoint charge of +7.45 pc (7.45 × 10-12 c. is fixed at the origin. another point charge of –4.28 pc is fixed on the y-axis, 2.79 mm from the origin. if you placed a proton at point p, which is on the x-axis, 9.83 mm from the origin, what would be the magnitude of the electric force on that proton?

The electric force between two charges and separated by distance can be defined as:

where,

Charge of proton

Force due to charge at the origin on the proton:

we need to calculate the distance between the charge on y-axis and the proton:

We will use the Pythagoras theorem,

Force between these two charges:

The negative sign depicts that it is an attractive force because unlike charges attract.

Now we need to find the net force on the proton. we cannot simply add the two forces because force is a vector quantity. so, first we need to measure the angular separation between the forces.

Now, we will write the forces in vector form and do vector addition.

Net force along x-axis:

Net force along y-axis:

Net force on proton by the two charges: