yang pintar fisika bantu dong, plissss makasii ya

1.
Sin θ = 4 cm / 20 cm = 1/5

Gaya pemulih = mg sin θ = 0,25 . 9,8 . 1/5 = 0,49 Newton
Jawaban : A

2.
F = k . Δx
F = 100 . 0,05
F = 5 N
Jawaban : D

3.
sin θ = 10 cm / 50 cm = 1/5

F = mg.sin θ
F = 0,1 .9,8. 1/5
F = 0,196 N
Jawaban A

4.
Dik: t = 1/2 s
f2 = 4,5 Hz
f1 = 5 Hz

Dit : ∆θ

Jawab :
∆θ = θ2 – θ1
∆θ = 2π φ2-2π φ1
∆θ = 2π (φ2- φ1)
∆θ = 2π (f2t-f1t)
∆θ = 2π [5(1/2) - 4,5(1/2)]
∆θ = 2π (1/2(5 – 4,5)
∆θ = 2π (1/4)
∆θ = 1/2 π
∆θ = 90˚
Jawaban : D