Answer:
1. Net force= 6 N to left
2. Unbalanced
3. Both people must apply same magnitude of forces in opposite direction which causes net force to be 0.
Explanation:
Since both forces have opposite direction then we have to subtract the magnitude and consider the direction of vector that has greatest magnitude. In this case, the left side (13N) has more magnitude than the right side (7N). Hence:
[tex] \displaystyle{ \sum \vec F = 13 \: \text{N}- 7\: \text{N}= 6 \: \text{N to left}}[/tex]
The vector arrow of net force will point to left side with magnitude of 6 N.
Since the net force is not zero. This means that the force is not balanced as an object still changes its motion from resting to moving. A balanced force would mean the net force is zero and an object will always remain as same condition. This can be referred to first Newton's law of motion.
We can make the force balanced by having both people acting same magnitude of force in opposite direction. The equation must result in:
[tex] \displaystyle{ \left | \vec F \right | = \left| - \vec F \right| }[/tex]
Magnitude of forces must equal for both sides and also have to act in opposite direction which causes net force to be zero:
[tex] \displaystyle{ \sum \vec F = 0}[/tex]
