Need help

For E, the answer to c is 102

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

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.

What is the increase in density of a medium due to wave travel?