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Bahan Ajar Elektronik
Fisika Kelas XI Semester 2
KUNCI JAWABAN
Latihan Pertemuan 1
1. τ = F r Sin θ
0
τ = (12) (2) Sin 60
τ = 12
2
2
2. ΣI =m AR A + m BR B
2
2
ΣI = (2)(1) + (1)(4-1)
2
2
ΣI = (2)(1) + (1)(3)
ΣI = 2 +9
ΣI = 11 Kg.m 2
3. Ek = Ek Translasi + Ek Rotasi
2
2
Ek = ½ m v + ½ I ⍵
2
V
2
Ek = ½ m v + ½ ( ½ m R ) ( / R) 2
2
Ek = ½ m v + ¼ m v 2
2
2
Ek = ½ (10)(8) + ¼ (10)(8)
Ek = 320 +160
Ek = 480 J
4. τ = I α
2
F.R = ½ m.R .α
m.g = ½ m R α
(4)(10) = ½ (8)(0,08) α
40 = 0,32 α
α = 125 rad/s 2
maka,
a = α R
a = (125) (0,08)
= 10 m/s 2
78
Fisika SMA/MA Kelas XI
