Esulfur burns easily .iron is attracted by magnets .the mineral made by sulfur and iron ,but it does not burn and it is not attracted by magnets .is it a mixture ? why ? and why not ?

Aman is trying to drag a small tree that he cut down. if the static coefficient of friction of the tree on the ground is 0.5 and the tree weighs 670 n, what is the minimum amount of horizontal force that the man will need to apply so that the tree will start moving? o a. 465 n o b. 230 n o c. 670 n o d. 335 n