hi , i have been preparing for the physics GRE and i m following the Yoni khan book of conquering the physics GRE, and i m kind of stuck in the very first problem..
A block opf mass 5 kg is positioned on an elclined plane at an angle 45 degree. A force of 10 N is applied to the block parallel to the ground, if the coefficient of kinetic friction is 0.5, what is the acceleration of the block?
i solved out the problem first for motion without kinetic friction. so
mg*sinx-F sinx = 20*sqrt 2............(1) net downward motion
the considering friction,
mu*mg*cos x= 25sqrt 2........(2) net upward motion
so the accelearion should be sqrt2 upward, but the solution says it should be sqrt up, where am i getting it wrong ?