Exercise l: True$/$False $[10$ points$]$

$1.$ Four main classes of Engineering Materials are: metals, ceramics, polymers, and composites.

$2.$ A material with a Poisson coefficient being zero will not change its volume during a uniaxial tensile test.

$3.$ Strain is dimensionless while stress has a dimension of a force.

$4.$ Yield failure is driven by shearing stresses but not tensile stresses

$5.$ Stress concentration factor depends on specific geometry and loading conditions.

$6.$ Fatigue failure is a consequence of reduced material properties after cyclic loading.

$7.$ The loss modulus of a pure elastic material is zero.

$8.$ Most polymers will lose it rubbery properties when temperature drops.

$9.$ For a glass fiber reinforced composites $($GRFCs$),$ the tensile strength is proportional to its glass fiber content.

$10.$GFRCs should not be used as a wall of a submarine due to its poor strength under compression.