Fused quartz possesses an exceptionally low coefficient of linear expansion, 5.50 × 10 − 7 ( ∘ c ) − 1 . suppose a bar of fused quartz of length 3.45 m at 20.0 ∘ c is heated to 235 ∘ c . by how much, in millimeters, would the bar expand?

To solve this problem we will use the concepts related to thermal expansion in a body for which the initial length, the coefficient of thermal expansion and the temperature change are related:

Where,

= Change in Length

= Coefficient of linear expansion

= Change in temperature

= Initial Length

Our values are:

Replacing we have,

Therefore the change in milimiters was 0.4126mm

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.