Okay I'm really stumped on this question and I would be really glad if someone can take me step by step on how to do this question... I have the answer but I have no clue how to obtain it! The Question is: I obtained the answer for the force of friction by just using Fhorizontal = cos55 * 100 = 58 N (answer is 57 N) Now.. to find the coefficient.. we need to know two things right? The force of friction which we have and the normal force. But how can we know what the normal force is if we are not given mass? However I'm not sure if that is the correct way to do it... if someone could explain how to get both answers step-by-step it would be great thanks!