How to Answer: What is a free-body diagram? When would you use one?
Advice and answer examples written specifically for a Mechanical Engineer job interview.
30. What is a free-body diagram? When would you use one?
How to Answer
Your interviewer will likely ask you knowledge-based questions to understand how well you are able to explain concepts to others. Be prepared for questions like this one by practicing a few possibilities ahead of time. In this case, free-body diagrams are taught in most introductory physics classes, and this question is sometimes asked as a starting point for further technical questions. You may be asked to draw one or simply describe what they are. Make sure to label gravitational force, normal force, frictional force, and any external forces applied to the body in question. You may also be asked to use a free-body diagram in the context of a real-world problem.
Written by Jason Toby on October 12th, 2020
Answer Example
"Free-body diagrams describe the forces acting on an object, showing them as vectors with both magnitude and direction. For example, a falling bowling ball would have a gravitational force vector pulling straight down. A rolling bowling ball would also have a normal force vector that is perpendicular to the surface it is rolling on. I would use a free-body diagram if I was trying to visualize the net forces acting on an object. Depending on the situation, I might follow up with a Finite Element Analysis model to analyze the expected behavior of the design, or I might come up with a set of equations to determine the amount of force required to achieve the design goal."
Written by Jason Toby on October 12th, 2020