Final answer:
The subject of the question is Physics, specifically classical mechanics, and the grade level is High School. The problem involves calculating the resultant of two forces combined at an angle and can be approached using vector addition or the Pythagorean theorem in a free-body diagram context.
Step-by-step explanation:
When analyzing the combination of two forces at an angle, the discipline involved is Physics. Specifically, this falls under the branch of classical mechanics that deals with the analysis of forces and their effects on motion. We can solve the problem of finding the resultant of two non-collinear forces by using methods such as vector addition or graphical methods.
In this scenario, forces of 36.5 and 19.5 pounds are combined at an angle of 63 degrees. To find the resultant force, one might use the law of cosines or the component method to break these forces into their respective northward and westward components. For another example, a free-body diagram showing a northward force of 64 N and a westward force of 38 N would allow us to calculate the net force by using the Pythagorean theorem, given that forces at right angles are involved.
To further illustrate these concepts with practical applications, consider exercises in physics where you must apply Newton's laws to solve for forces exerted on objects, such as the upward force a desk exerts on a physics book or the force exerted by muscles in lifting a weight. The resultant force, as well as work done by various forces, are key quantities that can be calculated and are crucial for understanding physical systems and their behaviors.