Tolong bantu nomor 5 dong

MOMENTUM
• HKM

p = peluru, s = pistol (senapan)
mp = 2 gr, vp = 0, vp' = 150 m/s
ms = 500 gr, vs = 0, vs' = ___?

HKM
Σp = Σp'
mp vp + ms vs = mp vp' + ms vs'
0 = 1 • 150 + 500 • vs'
vs' = - 0,3 m/s ← jwb
(berlawanan arah dengan gerak peluru)