x= Vx .t

= Vcos .t

= 21 . cos 30o.1,2

= 21 . . 1,2

= 21,8m

Untuk mencari t :

h = Vy . t + . g . t2

20 = 21 . sin 30o . t + . 10 . t2

20 = 10,5 . t + 5 . t2

4 = 2,1 . t + t2

t2 + 2,1t – 4 = 0

t12 =

=

=

=

=

t1 =

= 1,2 s

t2 =

= -3,35 s