Alan is using the equation mg sin A = umg cos A to determine the coefficient of friction, u, between a flat rock and a metal ramp. Find u to the nearest hundredth, if the rock begins to slide at 19º.

Answer 1

divide both sides by mg, where m ≠ g ≠ 0

sinA = ucosA
u = sinA/cosA = tanA
if A = 19°
u = tan19 = appr .344