report1-1

Clear[k, 
      c]
m = 1;
res1=InverseLaplaceTransform[ 1/(m*s^2 + c*s + k*2)*1/s, s, t ]

c = 1;
k = 1;
g1 = Plot[res1, {t, 0, 10}]

c = 1;
k = 2;
g2 = Plot[res1, {t, 0, 10}]

Show[g1, g2, PlotRange -> {{0, 10}, {-1, 1}}]

report1-2

Clear[c, 
      w]
R = 1;
res2=InverseLaplaceTransform[ s*c/(R*c*s + 1)*s/(s^2 + w^2), s, t ]

c = 1;
w = 0.1;
g3 = Plot[res2, {t, 0, 10}]

c = 1;
w = 1.0;
g4 = Plot[res2, {t, 0, 10}]

Show[g3, g4, PlotRange -> {{0, 10}, {-1, 1}}]