Question

A 50 cm silver bar shortens by 1.0 mm when cooled. How much was it cooled?​

Answer 1

actually this question is related to thermal expension .
use
L=L'(1-a.dt)
where L is length of metal when metal is cooled.
L' is initial length of metal
a is thermal coefficient of metal
dt is temperature difference from higher to lower
I hope you can solve this question