Final answer:
To calculate the net electric force on charge q1, one would apply Coulomb's Law to find the forces exerted by q2 and q3 on q1, taking into account the distance and the sign of each charge.
Step-by-step explanation:
The student is asking for the net electric force on a specific charge in a system of three point charges aligned in a straight line. To find the net force on charge q1, one must consider the forces from both of the other charges (q2 and q3) on q1, and then use Coulomb's Law to calculate the magnitude of these forces. The net force on q1 is the vector sum of the individual forces exerted by q2 and q3 on q1.
According to Coulomb's Law, the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. The force is attractive if the charges are of opposite signs and repulsive if the charges have the same sign.
To solve this problem, one would calculate the force F12 between q1 and q2, and F13 between q1 and q3. Since q2 is positive and q1 is negative, the force F12 will be attractive. Conversely, since q3 is negative like q1, the force F13 will be repulsive. The magnitudes of these forces are calculated and then subtracted (since they are in opposite directions) to find the net force acting on q1.