Home › AP Physics C: Mechanics › Physics › Friction, Drag, and Elasticity › The source rewrites the change-in-length equatio…
The source rewrites the change-in-length equation as stress equals Young's modulus times strain. What relationship does this restatement draw?
AIt proves that Young's modulus has the same units as force
BIt shows that stress and strain are always numerically equal to each other
CIt treats stress like force and strain like deformation, mirroring Hooke's law
DIt shows that strain has units of newtons per square meter
Answer & Solution
Correct answer: C. It treats stress like force and strain like deformation, mirroring Hooke's law
1. Stress is defined as force divided by area, and strain is defined as change in length divided by original length.
2. Writing stress equal to Young's modulus times strain has the same structure as force equal to a constant times deformation.
3. This is stated explicitly: the equation is analogous to Hooke's law, with stress playing the role of force and strain playing the role of deformation.
4. Stress and strain have different units, since strain is unitless and stress carries units of newtons per square meter, so they are not numerically interchangeable.
5. Young's modulus carries the same units as stress, not the units of force alone, since it must convert a unitless strain into a stress value.
_Source: OpenStax College Physics (CC BY 4.0), Ch 5 "Further Applications of Newton's Laws: Friction, Drag, and Elasticity", section 5.3 Elasticity: Stress and Strain_
Related questions
According to the source, at roughly what point in life does the gradual physiological reduIf human arteries were rigid instead of elastic, what would you notice about your pulse, aA human tendon shows a nonlinear stress-strain curve. What does the source call the very fWhat example does the source give of a practical application of bulk compression on solidsUnlike most materials, what unusual behavior does water show when it freezes, according toAt a depth of 5.00 km in the ocean, the force per unit area on seawater is 5.00 times ten It is relatively easy to compress a gas but extremely difficult to compress a liquid or a What does the source say about the shear moduli of liquids and gases?