1. The problem statement, all variables and given/known data A block of mass 50 kg is free to slide on a frictionless inclined plane that makes an angle of 20° with respect to horizontal. A force F is applied as shown in the drawing pulling parallel to the incline. As a result, the block accelerates up the plane at 4 m/s2. known: m= 50 kg a= 4 m/s^2 Angle = 20 degrees 2. Relevant equations F=ma Fcos(theta) 3. The attempt at a solution F= 50kg* 4m/s2 = 200 N 200cos(20)=187.9= F x-direction * The explanation shows me F- 167 N = 200N F=367N But I don't know which equation this comes from or where the 167 comes from.