Final answer:
Two force members in a situation could be contact forces like the forces exerted by a chair and table on a student, or a field force such as gravity acting on the student. If force B is greater than force A, acting in the opposite direction, the object will move towards the direction of force B. Free-body diagrams are essential tools for illustrating forces acting on an object.
Step-by-step explanation:
In each situation, identifying two force members involves understanding the types of forces acting on an object. Contact forces are the result of direct physical interactions. For instance, in the case of a student sitting on a chair, the chair exerts a contact force on the student's posterior (force C), and the table exerts another contact force on the student's forearms (force I). Field forces, on the other hand, occur due to the presence of a field and do not involve physical contact. For example, Earth's gravitational field exerts a gravitational force (w) on the student, representing his weight.
When analyzing which direction an object will move when two forces are acting on it, such as force A to the left and force B to the right, with force B being greater than force A, the object will move in the direction of the greater force, which in this case is to the right.
To demonstrate the interaction of forces via free-body diagrams, you can follow these steps:
- Identify the masses you wish to analyze.
- Draw a free-body diagram and sketch the forces acting on each mass, noting the distance between their centers of mass.
- Apply Newton's second law of motion to determine the movement of each mass.
When drawing a free-body diagram for two perpendicular forces, the force arrows will be drawn at a right angle to one another (option a).
It is crucial to remember that each action has an equal and opposite reaction, which means that forces always come in pairs.