1. Sketsalah grafik-grafik dari fungsi berikut,

a. Y=Sin3x ; b. Y=3Cosx ; c. Y=2Sinx + Cos3x

a. Y=Sin3x

х y0 0.000030 1.000045 0.707160 0.000090 -1.0000120 0.0000135 0.7071150 1.0000180 0.0000210 -1.0000225 -0.7071240 0.0000270 1.0000300 0.0000315 -0.7071330 -1.0000360 0.0000

0 30 60 90 120 150 180 210 240 270 300 330 360 390

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

b. Y=3Cosx

х y0 3.000030 2.598145 2.121360 1.500090 0.0000120 -1.5000135 -2.1213150 -2.5981180 -3.0000210 -2.5981225 -2.1213240 -1.5000270 0.0000300 1.5000315 2.1213330 2.5981360 3.0000

0 30 60 90 120 150 180 210 240 270 300 330 360 390

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

c. Y=2Sinx + Cos3x

х y0 1.000030 1.000045 0.707160 0.732190 2.0000120 2.7321135 2.1213150 1.0000180 -1.0000210 -1.0000225 -0.7071240 -0.7321270 -2.0000300 -2.7321315 -2.1213330 -1.0000360 1.0000

0 30 60 90 120 150 180 210 240 270 300 330 360 390

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

2. Diketahui : y(t)=y0Sint

X(t)=0,1m

M = 2000kg

y0 =0.2m

=157.08 rad/s

Ditanya : K(kekakuan) dan C(redaman) ?

Jawab :

K= my0

jadi, K=20000.2

=10000kg /m

xy=0.1

0.2=0.5

xy={1+(2 ζ )2

(2 ζ)2 }1/2

→

0.25 = 1+(2 ζ )2

(2 ζ)2 →

-0.75 = 4 ζ 2

4 ζ 2

ζ=0.3779645

C = ζ∗Cr=ζ∗2∗√K∗m

C= 0.3779645 * 2*√10000∗(2000/9.81) = 1079.348 kg.s/m