A test of driver’s perception/reaction time is being conducted on a special testing track with level, wet pavement and a driving speed of 55 mile/hour. When the driver is sober, a stop can be made just in time to avoid hitting an object that is first visible 425 ft ahead. After a few drinks under exactly the same condition, the driver fails to stop in time and strikesan object at a speed of 35 mi/hour. Determine thedriver’s perception/reaction time before and after drinking.

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?