Final answer:
To accurately determine a vertical distance for a moment when it is difficult, trigonometry should be used to resolve components and analyze problems in physics. This approach is essential in dealing with inclined planes, projectile motion, and kinematic equations.
Step-by-step explanation:
If finding the vertical distance for a moment is difficult, the best approach is to use trigonometry. Disregarding the vertical distance, substituting with horizontal distance, or using only external forces would lead to an incorrect analysis of the problem. Trigonometry allows you to understand the relationship between the angles and the sides of a triangle, which is particularly useful in problems involving inclined planes or forces at angles.
For example, if you need to find the vertical component of a force or displacement, you might use the sine or cosine functions, depending on the known angle and the side length. Similarly, in projectile motion, analyzing the vertical and horizontal motions separately with trigonometry is critical to solving the problem accurately. Trigonometry provides tools to resolve forces into components along an incline or to determine an object's displacement in the kinematic equations of motion.