A particular metal has a work function of $2\mathrm{.}48.$ Light of three different wavelengths $450($blue light$),$

$560($yellow light$),$ and $650($red light$)$ shines on the metal.

a$.$ Which wavelength or wavelengths cause electrons to be ejected from the metal? Explain your

reasoning.

b$.$ For those wavelengths that cause the ejection of electrons, determine the kinetic energy $($in $)$ of the