A $550lb$ block is supported by a horizontal floor. The coefficient of static friction mu between the block and the floor is assumed to be $0\mathrm{.}5.$ Calculate the force $P$ required to cause motion to impend. The force is applied to the block $($a$)$ horizontally and $($b$)$ downward at an angle of ${35}^{**}$ with horizontal. $($Do not forget to change the values on the pictures to what is provided in the text of the problem$).$