Note 1: Balanced forces do not cause alterization motion or movement. This is because of the fact that balanced forces are equal in size and in opposite directions. Consequently, this leads to cancellation and ultimately no movement.The net force for balancing forces is always 0.
Think of it this way: Take your right hand and left hand. Press them together; palm-to palm and five fingers to five fingers. Now apply equal amount of pressure (your force) as you push them in opposite directions (left hand left direction right hand right direction) Does any change in movement occur?
Note 2: Unbalanced forces are the forces that cause change in movement and motion. When two unbalanced forces are exerted in opposite directions, the overall force (or net force) is the difference between the two forces and the direction is in favor for the larger force. Think of it this way. Repeat the exercise I shown you in Note 1, but this time, make apply more force in comparison to the other hand. Your right/left hand's force overpowers the weaker force of the opposite hand. The direction is in favor to your right/left hand (since they obtain the bigger force) as your hands move to the right or left side. This is an example of unbalanced forces at play.
Q22: The two forces on the left and right side are balanced given that their force is equal in size and they are in opposite directions. The two forces northwards and southwards are unbalanced forces since they are not equal in size but are opposite in direction. Recall in note 2 when I given the formula to find the net force for unbalanced forces. Its the difference (subtraction) between the bigger force and smaller force. 5 - 2 = 3. Therefore the net force for question 22 is 3.The direction is in the bigger force's direction, therefore southwards.
Q24: Is a balanced force. Therefore the net force is 0. I don't think there is technically any direction per say.
These base pair relationships are often called Chargaff's rules of DNA base pairing, named after the Columbia University scientists who observed that there are equal molar concentration of A & T, as well as G & C in most DNA molecules.
