When thermal energy of a substance increases, it's entropy(randomness) & Kinetic energy increases.
For more appropriate answer, you should put the options 'cause there could be more than one answer for this question.
Answer:
The new length is 50.00885m
Explanation:
linear thermal expansion coefficient Fe 11.8e-6 /K
The new length can be determined using the following equation:
∆L/L = α∆T, where α is linear thermal expansion coefficient
∆L = Lα∆T = 50(11.8e-6)(35-20) = 0.00885 m
New length = ( 50.000 + 0.00885)m =
New length = 50.00885 m