Jawaban:

. m₁.v₁ + m₂.v₂ = m₁.v₁' + m₂.v₂'

50.5 + 200.0 = 50.v₁' + 200 v₂'

250 = 50 v₁' + 200 v₂'

------------------------------- : 50

5 = v₁' + 4 v₂'

v₁' = 5 - 4 v₂'..... (pers 1)

Ek₁ + Ek₂ = Ek₁' + Ek₂'

m₁. v₁² + m₂.v₂ = m₁.v₁' + m₂.v₂'

----------------------------------------------------------------------- x 2

m₁.v₁² + m₂.v₂² = m₁.v₁'² + m₂.v₂'²

50.5² + 200.(0)² = 50.v₁'² + 200.v₂'²

1250 = 50 v₁'² + 200 v₂'²

-------------------------------------- : 50

25 = v₁'² + 4 v₂'² ... pers 2

subtitusikan pers 1 ke 2

25 = (5 - 4v₂')² + 4 v₂'²

25 = (25 - 40 v₂' + 16 v₂'²) + 4 v₂'²

20 v₂'² = 25-25+ 40 v₂'

20 v₂'² = 40 v₂'

------------------------ : 20 v₂'

v₂' = 2 m/s sesuai arah orang yang meloncat

utk sementara, berlanjut setelah kk tidak sibuk.

2. ms = 5 kg --> vs = 0

mp = ? --> vp = 0

vp' = 50 m/s

ms.vs + mp.vs = ms.vs' + mp.vp'

0 + 0 = 5. vs' + mp. 50

5 vs' = - 50 . mp

vs' = -10 mp

semisal jika massa peluru diketahui = 20 gr = 0,02 kg

maka vs' = -10.(0,02) = -0,2 m/s

3). m₁ : m₂ = 3 : 5

v₁' = 50 m/s

Ek₁' = Ek₂'

1/2 m₁.v₁'² = 1/2 m₂.v₂'²... coret yang digaris bawahi

m₁.v₁'² = m₂.v₂'²

3. 50² = 5.v₂'²

v₂'² = 3. 50.50 / 5

= 1500

v₂' = √1500

= 10√15 m/s