What is the first sing of dehydration

Does anyone know how to solve this problem? i really need . i made an attempt but i just cant get it. a metal rod is 25.000 cm long at 25.0 degrees celsius. when heated to 102.0 degrees celsius, it is 25.054 cm long. what is the coefficient of linear expansion for this metal.

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.

What you see with your eyes is a form of energy. a. light b. heat c. chemical d. electrical