#m=12 kg# #g=9,81 N/(kg)# #"change value" pi/3 "to degree"# #theta =(180/cancel(pi)).(cancel(pi)/3)# #theta=60^o# #cos60^o=0,866# #h=8*0,866=6,928 meters# #"it gains Potantial Energy when object raises to the point of B"# #E_p=m*g*h# #E_p=12*9,81*6,928# #E_p=815,56416##"joule"# #E_p="work doing between the point A and B"# #W=815,56416##"joule"#