[د.امير]

Q5
solid materials expand upon heating and contract when cooled. The change in length is expressed by:
ΔL = L0 α ΔT
where
L0 original length,
α = thermal coefficient of expansion
and
ΔT is change in temperature

ΔL= 65 * 29 10 -6 * (-45 -18) = -0.119 m (contraction