How can i solve the collision & cm worksheet

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.

J. j. thomson’s experiment disproved the theory that an atom

The average time that it takes for the car to travel the first 0.25m is s. the average time to travel just between 0.25 m and 0.50 m is s. given the time taken to travel the second 0.25 m section, the velocity would be m/s.