Sebuah benda massa 100 gr bergetar harmonis dengan amplitudo 20, cm dan frekwensi 20/phi Hz. pada saat simpangan 12 cm, tentukan : a) kecepatan getaraan b) EK getaram c) EP getaran d) E Total
Diket : Benda bermassa, m = 100 gram = 0,1 kg Amplitudo, A = 20 cm Frekuensi, f = 20/pi Hz Saat simpangan, Y = 12 cm = 0,12 m
Tanya : A. Kecepatan getaran ----------------------------- V = omega•akar (A^2 - Y^2) V = 2•pi•f• akar (A^2 - Y^2) V = 2•pi•20/pi• akar (20^2 - 12^2) V = 40• akar (400 - 144) V = 40• akar (256) V = 40• 16 V = 640 cm/s V = 6,4 m/s
B. Ek getaran Ek = 1/2•m•v^2 Ek = 1/2•0,1•(6,4)^2 Ek = 0,05• 40,96 Ek = 2,048 J
C. Ep getaran Ep = 1/2•k•y^2 Ep = 1/2•m•omega^2•Y^2 Ep = 1/2•m•(2•pi)^2•Y^2 Ep = 1/2•m•4•pi^2•Y^2 Ep = 2•m•pi^2•Y^2 Ep = 2•0,1•pi^2•(0,12)^2 Ep = 288•pi^2•10^-5 J Ep = 288•10•10^-5 J (anggap pi^2 = 10) Ep = 0,0288 J
D. Energi Total Em = Ek + Ep Em = 2,048 + 0,0288 Em = 2,0768 J
Verified answer
Diket :Benda bermassa, m = 100 gram = 0,1 kg
Amplitudo, A = 20 cm
Frekuensi, f = 20/pi Hz
Saat simpangan, Y = 12 cm = 0,12 m
Tanya :
A. Kecepatan getaran
-----------------------------
V = omega•akar (A^2 - Y^2)
V = 2•pi•f• akar (A^2 - Y^2)
V = 2•pi•20/pi• akar (20^2 - 12^2)
V = 40• akar (400 - 144)
V = 40• akar (256)
V = 40• 16
V = 640 cm/s
V = 6,4 m/s
B. Ek getaran
Ek = 1/2•m•v^2
Ek = 1/2•0,1•(6,4)^2
Ek = 0,05• 40,96
Ek = 2,048 J
C. Ep getaran
Ep = 1/2•k•y^2
Ep = 1/2•m•omega^2•Y^2
Ep = 1/2•m•(2•pi)^2•Y^2
Ep = 1/2•m•4•pi^2•Y^2
Ep = 2•m•pi^2•Y^2
Ep = 2•0,1•pi^2•(0,12)^2
Ep = 288•pi^2•10^-5 J
Ep = 288•10•10^-5 J
(anggap pi^2 = 10)
Ep = 0,0288 J
D. Energi Total
Em = Ek + Ep
Em = 2,048 + 0,0288
Em = 2,0768 J
________
)|(
FZA