Question

An electron traveling horizontally from west to east enters a region where a uniform electric field is directed upward. What is the direction of the electric force exerted on the electron once it has entered the field?

Short answer

Answer: The electric force exerted on the electron is in the southeast direction (downward and eastward).

Step-by-step solution

Analyze the electric field and electron charge

The electric field is directed upward. Since the electron has a negative charge, the electric force acting on it will be in the opposite direction of the electric field. Therefore, the electric force on the electron will be directed downward.

Combine directions of electron movement and electric force

The electron is moving horizontally from west to east, and the direction of the electric force is downward. Combining these two directions, the overall direction of the electric force exerted on the electron will be southeast (downward and eastward).

Conclusion

The electric force exerted on the electron, once it has entered the field, is in the southeast direction (downward and eastward). This is due to the combination of the electron's horizontal movement from west to east and the downward direction of the electric force, which is opposite to the upward-directed electric field.