posted by Daniel .
A mass of 10kg is placed on the top of a plane inclined at 45 degrees to the horizontal and allowed to slide down. What is the acceleration of the mass if the frictional force opposing is 3.2N.
mg = 10kg * 9.8 = 98N @ 45deg.
Fp = 98*sin(45) = 69.3N = Force acting parallel to plane and downward.
Fn = Fp - Ff = 69.3 - 3.2 = 66.1N.
a = Fn / m = 66.1 / 10kg = 6.61m/s^2.