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 \mathrm{m}^{4}. The deflection is also dependent on Young’s modulus E, which has units \mathrm{N} / \mathrm{m}^{2}. Then x depends on L according to
Answer Choices
A. x \propto \sqrt{L}
B. x \propto L
C. x \propto L^{2}
D. x \propto L^{3}
E. x \propto L^{4}