One object exerts a force of magnitude F1 on another object and experiences a force of magnitude F2 in return. What is true for F1 and F2?

The relation between F1 and F2 is : F1 = - F2. That is the forces are equal in magnitude but opposite in direction.

Explanation:

According to Newton's 3rd law of motion statement, it states that for all actions there is equal but opposite reaction. This law is also known as the law of symmetry. It means that forces occur in pairs in any conditions. An object will not apply force on other object without experiencing the force on itself. This means when an object exerts force F1 on another object, it also exerts the same force of same magnitude on itself in opposite direction to the force it exerted on another object.