Tlong di jawab buat besok

4.
Diketahui
r = 3,84 x 10^5 km
T = 28 hari
   = 28 x 24 jam
   = 672 jam

Ditanya
kecepatan sudut = ω = ...?
kecepatan linear = v = ...?
percepatan sentripetal = as = ...?

Jawab
ω = 2π / T
    = 2π / 672
    = π/336 rad/jam

v = ω x r
   = π/336 x 3,84 x 10^5
   = 0,03 x 10^5 km/jam
   = 0,3 x 10^4 km/jam

as = v² / r
     = (0,03 x 10^5)² / (3,84 x 10^5)
     = 0,000234 x 10^5 km/jam²
     = 23,4 km/jam²

5.
Diketahui
r = 3 m
n = 120 putaran
t = 1 menit = 60 detik

Ditanya
frekuensi = f = ...?
periode = T = ...?
kecepatan sudut = v = ...?
kecepatan linear = ω = ...?

Jawab
f = n / t = 120 / 60 = 2 Hz

T = 1 / f = 1/2 = 0,5 detik

v = 2πrf
   = 2π x 3 x 2
   = 12π m/s

ω = 2πf
    = 2π x 2
    = 4π rad/sec