ORBITAL MECHANICS FOR ENGINEERING
STUDENTS UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS
COMPREHENSIVE STUDY GUIDE
●● Kinetic frictional force
Answer: Falls to a lower value than the static frictional force once
motion is initiated and sliding begins, remaining relatively constant
during relative motion.
●● Static Frictional force
Answer: Always equal magnitude to the force tending motion up to a
maximum threshold (μs × Fn), preventing stationary objects from
starting to slide.
●● Stress
Answer: P / A (P = force, A = Area) representing the internal distribution
of force per unit area within a material undergoing external loading.
●● Hydrostatic Pressure
Answer: P = F/A (p = pressure, F = Force (n), A = area (m^2)) acting
uniformly in all directions within a fluid at rest or under omnidirectional
stress.
,●● Pascals Principal
Answer: F(1) / A(1) = F(2) / A(2), stating that pressure applied to an
enclosed incompressible fluid is transmitted undiminished to every part
of the fluid and container walls.
●● Strain
Answer: e / l (e = Extension, L = original length), quantifying the
fractional deformation or relative change in dimension resulting from
applied stress.
●● Stress/Strain Curve
Answer: Measures mechanical properties of a material in relation to the
ratio and relationship of stress and strain up to failure.
●● Young's Modulus
Answer: Ratio of stress and strain within the elastic limit (Hooke's law
region), representing the stiffness and slope of the elastic deformation
portion.
●● Hooke's Law
Answer: f = kx (k = stiffness (N/m), x = extension (m)), stating that the
extension of an elastic object is directly proportional to the applied load
up to the proportional limit.
, ●● Proportional Limit
Answer: The point when stress and strain stop being directly
proportional, marking the end of linear elastic behavior on the stress-
strain curve.
●● Elastic Limit
Answer: The point where all further deformation is permanent and not
elastic, marking the threshold between elastic and plastic deformation.
●● Upper Yield Point
Answer: The point where a maximum amount of stress is required to
initiate yielding in ductile materials like mild steel before dislocation
movement eases.
●● Lower Yield Point
Answer: The point of stable state where the material continues to yield
at a lower stress level than the upper yield point due to runaway
dislocation propagation.
●● UTS
Answer: The maximum amount of stress reached by a material on the
engineering stress-strain curve before it begins to neck and localized
cross-sectional reduction occurs.
STUDENTS UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS
COMPREHENSIVE STUDY GUIDE
●● Kinetic frictional force
Answer: Falls to a lower value than the static frictional force once
motion is initiated and sliding begins, remaining relatively constant
during relative motion.
●● Static Frictional force
Answer: Always equal magnitude to the force tending motion up to a
maximum threshold (μs × Fn), preventing stationary objects from
starting to slide.
●● Stress
Answer: P / A (P = force, A = Area) representing the internal distribution
of force per unit area within a material undergoing external loading.
●● Hydrostatic Pressure
Answer: P = F/A (p = pressure, F = Force (n), A = area (m^2)) acting
uniformly in all directions within a fluid at rest or under omnidirectional
stress.
,●● Pascals Principal
Answer: F(1) / A(1) = F(2) / A(2), stating that pressure applied to an
enclosed incompressible fluid is transmitted undiminished to every part
of the fluid and container walls.
●● Strain
Answer: e / l (e = Extension, L = original length), quantifying the
fractional deformation or relative change in dimension resulting from
applied stress.
●● Stress/Strain Curve
Answer: Measures mechanical properties of a material in relation to the
ratio and relationship of stress and strain up to failure.
●● Young's Modulus
Answer: Ratio of stress and strain within the elastic limit (Hooke's law
region), representing the stiffness and slope of the elastic deformation
portion.
●● Hooke's Law
Answer: f = kx (k = stiffness (N/m), x = extension (m)), stating that the
extension of an elastic object is directly proportional to the applied load
up to the proportional limit.
, ●● Proportional Limit
Answer: The point when stress and strain stop being directly
proportional, marking the end of linear elastic behavior on the stress-
strain curve.
●● Elastic Limit
Answer: The point where all further deformation is permanent and not
elastic, marking the threshold between elastic and plastic deformation.
●● Upper Yield Point
Answer: The point where a maximum amount of stress is required to
initiate yielding in ductile materials like mild steel before dislocation
movement eases.
●● Lower Yield Point
Answer: The point of stable state where the material continues to yield
at a lower stress level than the upper yield point due to runaway
dislocation propagation.
●● UTS
Answer: The maximum amount of stress reached by a material on the
engineering stress-strain curve before it begins to neck and localized
cross-sectional reduction occurs.
