• v=kte=10m/s fy=-mg+FN=0 • a= 0m/ 2 =2Kg(-10m/s)+FN=0 • =0.4 s FN=20N • m=2Kg F=m(a) F-10-FN( )=m(a) s • DCL: F-10-20(0.4)=2Kg(0m/ ) 2 F-10-8=0 F=18N