Assume that the wavelengths of photosyntheticallyactive radiations (PAR) are uniformly distributed at integernanometers in the red spectrum from 675 to 700 nm. a. What are the mean and variance of the wavelength distributionfor this radiation?b. If the wavelengths are uniformly distributed at integernanometers from 75 to 100 nanometers, how do the meanand variance of the wavelength distribution compare to theprevious part? Explain.

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?