Physics - Materials

• What is an homogenous equation?


  An equation where you convert units to base units.
• What is density?


  Mass per unit volume
• How can you calculate the density of an alloy?


  P = (P1V1+P2V2+….)/V
• What is Hooke's Law?


  The extension of a spring is proportional to the force needed to extend it
• What is the effective spring constant for a spring in parallel?


  k = k1 + k2 + ...
• How can energy in a spring be determined?


  The area underneath a force-extension curve equals the work done on the spring
• What is tensile stress?


  The force per unit area of a cross-section in a solid perpendicular to the cross section
• What is the elasticity of a solid?


  The ability of a solid to return to its shape after being deformed
• What is the elastic limit of a material?


  The point beyond which a wire is permanently stretched
• What is plastic deformation?


  Deformations of a solid beyond its plastic limit
• What is ultimate tensile stress or tensile strength?


  The stress needed to break a solid material
• How would you describe a brittle material?


  A material that will snap without stretching or bending under stress
• How would you describe a strong material?


  A material tested with a high ultimate tensile strength (UTS)
• How would you describe a ductile material?


  A material that can be drawn out into a wire
• How would you describe a stiff material?


  A material requiring a lot of force to extend
• What is the kind of proportionality in relation to force and extension?


  Force is directly proportional to the extension
• What is the effective spring constant for a springs in series?


  1/kT = 1/k1 + 1/k2 +….
• What is tensile strain?


  Extension per unit length of a solid when deformed
• What is Young’s modulus?


  Stress/Strain (Assuming the limit of proportionality hasn’t been exceeded)