bantu dong.. sama cara nya

14.
ΔEp = Ep maks - Ep B
ΔEp = mgh - mg1/4h
ΔEp = mg(h-1/4h)
ΔEp = mg(3/4h)

Energi sifatnya kekal maka Ek = ΔEp
Ep/Ek = Ep B/ΔEp
Ep/Ek = mg1/4h / mg3/4h
Ep/Ek = 1/4 / 3/4
Ep/Ek = 1/3
Ep : Ek = 1 : 3

15.
hA = 2,4 m
hB = 1,2 m
Kekekalan energi :
Em awal = Em akhir
Ep A = Ep B + Ek B
mghA = mghB + Ek B
3.10.2,4 = 3.10.1,2 + Ek B
72 = 36 + Ek B
Ek B = 72 - 36
Ek B = 36 J