Physics - Elasticity Question with Solution | TestHub
The Young's modulus of a material measures how stiff it is; the larger the value of the more stiff the material. Consider a solid, rectangular steel beam which is anchored horizontally to the wall at one end and allowed to deflect under its own weight. The beam has length , vertical thickness , width , mass density and Young's modulus ; the acceleration due to gravity is . What is the distance through which the other end moves? (Hint: you are expected to solve this problem by eliminating implausible answers. Also note that all the options are dimensionally correct.)
Options:
Answer:
Solution:
Greater means less bending, so the deflection must decrease with .
A thicker beam bends less, so the deflection must decrease with .
Option (A) increases with and (B) has no , (D) increases with . All three are rejected.
Only option (C) decreases with both and and grows with and :
