GERAK HARMONIS SEDERHANA

▶Persamaan GHS

A = 5 cm

f = 2 Hz

Persamaan umum

y = A sin θ

y = 5 sin θ

y = 3 cm

a) θ = __ ?

y = 5 sin θ

3 = 5 sin θ

sin θ = 3/5

θ = 37° ✔

b) v = __ ?

y = 5 sin θ

y = 5 sin ωt

v = dy / dt

v = d (5 sin ωt) / dt

v = 5ω cos ωt

v = 5ω cos θ

ω = 2π f

ω = 2 × 3,14 × 2

ω = 12,56 rad/s

v = 5 × 12,56 × cos 37°

v = 50,24 m/s ✔

c) a = __ ?

v = 5ω cos ωt

a = dv / dt

a = d (5ω cos ωt) / dt

a = -5ω² sin ωt

a = -5ω² sin θ

ω² = (2π f)²

ω² = 4π² f² ... (π² ≈ 10)

ω² = 4 × 10 × 2²

ω² = 160

a = -5 (160) × sin 37°

a = -480 m/s² ✔