Originally Posted by **Johulus** ... I get that the friction coefficient is equal to sine of the inclination angle divided by cosine of the inclination angle. |

Yes, this is correct if the object slides at constant rate (i.e. zero acceleration).

Originally Posted by **Johulus** Task says I should calculate the friction coefficient if the inclination is: a) 30° b) 45° c) 60° . I encounter a problem when I want to determine the friction coefficient for slopes that have 45°or 60°. When I insert the values in equation , I get a value that is equal to 1, which is very odd, or I get a value greater than 1. And as I know, the friction coefficient should be less than 1. |

There is no rule that says the friction coefficient must be less than 1.

Originally Posted by **Johulus** One another thing that is odd about this is that I got higher values for the friction coefficient when the slope was steeper, but I would expect the values of the friction coefficient to be smaller proportionally to the increase in inclination. |

If the slope is very small, the coefficient must be small - otherwise the friction force would be too large and the object would decelerate. And if the slope is large, the coefficient must be large in order to keep the object from accelerating.