Solve each of the following problems with the trial solution method. Identify the free, forced, transient, and steady-state responses.
a. x¨ + 8x˙ + 15x = 30 x(0) = 10 x˙(0) = 4
b. x¨ + 10x˙ + 25x = 75 x(0) = 10 x˙(0) = 4
c. x¨ + 25x = 100 x(0) = 10 x˙(0) = 4
d. x¨ + 8x˙ + 65x = 130 x(0) = 10 x˙(0) = 4

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?