Final answer:
When drawing a free-body diagram, forces in equilibrium that are acting on an object are represented with arrows at a right angle to one another, signifying that they are perpendicular. These forces ensure the object remains in a state of balance. This principle applies across various physics scenarios including blocks on springs, lever arms and objects on inclined planes.
Step-by-step explanation:
When drawing a perpendicular force in relation to small triangles, such as those found in physics problems, it's pivotal to understand the relationship between the forces at play. For instance, suppose we have two forces acting on an object in equilibrium. According to the information provided, one important principle that emerges is that these forces are perpendicular to each other. Hence, correct representation on a free-body diagram would show two force arrows drawn at a right angle to one another. This setup illustrates the forces acting in different but complementary directions, maintaining the object's equilibrium.
If for example we have a block on a spring on a frictionless surface, there would be a normal force and the object's weight acting perpendicular to the surface. Meanwhile, the force due to the spring acts parallel to it. Similarly, when considering the force applied to a lever arm, the most efficient application of force is perpendicularly at the furthest point from the pivot.