The maximum electron energy in a photoelectric experiment is 2.8 eV. When the frequency of the illuminating radiation is decreased by 50%, the maximum electron energy drops to 1.1 eV. Find a) the original wavelength (and frequency) of the illuminating radiation and b) the work function of the emitting surface

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm