Ahelical compression spring is wound using 2.5 mm diameter music wire. the spring has an outside diameter of 31 mm with squared ground ends, and 14 total coils. a) estimate the spring rate b) estimate the static load corresponding to the yield strength c) what should the free length be to ensure that when the spring is compressed solid the torsional stress does not exceed the yield strength? d) determine if the spring might buckle in service.

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?