Hydrogen also produces spectral lines at radio wavelengths, notably at 21.1 cm. If a galaxy is moving away from us at 23% of the speed of light, at what wavelength will we detect this line? Convert this into frequency.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

the body's situation won't change the forces are equal opposit and on the same body

the answer would be 32*f

the force on the thing and the distance the force moves the thing