Soal nomor 2 dan 3 dengan cara?

2][
Nₜ = 25% Nₒ = ¼ Nₒ
T = 4000 tahun
t = __?

Nₜ = Nₒ • (½)^(t/T)
¼ Nₒ = Nₒ • (½)^(t/4000)
(½)² = (½)^(t/4000)
2 = t/4000
t = 8000 tahun ✅


2][
h₁ = 15 m
h₂ = 15 - ⅔ × 15 = 5m
Ek₂ = __?

Ek₂ + Ep₂ = Ek₁ + Ep₁
Ek₂ = Ep₁ - Ep₂
Ek₂ = m g (h₁ - h₂)
Ek₂ = m g (15 - 5)
Ek₂ = 10 m g ✅