Physics Guide
Sign in
Back to Problems
F = ma (First 10)
Dimensional Analysis
FMA-2018B-06 · 2018B F = ma (AAPT)

2018 F = ma Exam B — Question 6

A massless beam of length L is fixed on one end. A downward force F is applied to the free end of the beam, deflecting the beam downward by a distance x. The deflection x is linear in F and is inversely proportional to the cross-section moment I, which has units m4. The deflection is also dependent on Young’s modulus E, which has units N/m2. Then x depends on L according to √
Source: Question 6, 2018 F = ma Exam B, © 2018 American Association of Physics Teachers (AAPT) and the U.S. Physics Team. Adapted by PhysicsTrainer: reformatted into a separate question and answer choices for online multiple-choice practice; any shared setup from nearby questions is repeated here. Not affiliated with or endorsed by AAPT or the U.S. Physics Team.