A 105-kg rubber mat is pushed on a dry concrete floor. What is the coefficient of static friction, if the force required to start the mat sliding is 1030 N? Use "us" to represent coefficient of static friction.

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.