Jawabanmu

2014-06-04T18:07:03+07:00
Dik: f= 40cm M= 1/2 kali s`= 20 cm Jwb = 1/s = 1/f - 1/s` 1/s = 1/40 - 1/20 1/s = 1/40 - 2/40 1/s = - 1/40 s = - 40/1 s = -40