57 Unit 6 Review
Key Takeaways
Learner Objectives
- Identify classes of levers and explain advantages and disadvantages of each classes in terms of mechanical advantage and range of motion.[2]
- Apply lever and static equilibrium concepts to solve for forces and calculate mechanical advantage in scenarios involving levers. [3]
- Identify and define the features of a stress-strain curve, including stress, strain, elastic region, elastic modulus, elastic limit, plastic region, ultimate strength, and fracture/rupture.[2]
- Apply the Hooke’s Law along with the definitions of stress, strain, and elastic modulus to calculate the deformations of structures. [3]
referring to a lever system, the force applied in order to hold or lift the load
the force working against the rotation of a lever that would be caused by the effort
the point on which a lever rests or is supported and on which it pivots
the central point, pin, or shaft on which a mechanism turns or oscillates
perpendicular distance between the line of action of a force causing a torque and the pivot about which the torque occurs
in a lever, the distance from the line of action of the effort to the fulcrum or pivot
shortest distance from the line of action of the resistance to the fulcrum
There are three types or classes of levers, according to where the load and effort are located with respect to the fulcrum
ratio of the output and input forces of a machine
distance or angle traversed by a body part
the force that is provided by an object in response to being pulled tight by forces acting from opposite ends, typically in reference to a rope, cable or wire
reduction in size caused by application of compressive forces (opposing forces applied inward to the object).
a physical quantity that expresses the internal forces that neighboring particles of material exert on each other
the measure of the relative deformation of the material
measures of resistance to being deformed elastically under applied stress, defined as the slope of the stress vs. strain curve in the elastic region
the maximum stress a material can withstand
region of the stress vs. strain curve for which stress is proportional to strain and the material follows Hooke's Law
the range of values for stress and strain values over which a material returns to its original shape after deformation
the maximum stress that can be applied to a material before it leaves the linear region
the range of values for stress and strain over which a material experiences permanent deformation
the value of the stress (yield stress) and strain (yield strain) beyond which a material will maintain some permanent deformation
liable to break or shatter due to relatively inability to deform under stress (not ductile)
able to be deformed without failure, pliable, not brittle
