Using c=λν and e=hν (where h or planck’s constant is 6.626 *10 ⁻³⁴js). find the energy that a wavelength has if it has a wavelength of 3.000*10⁷ nm.

I attached the working and the answer to both questions below.

Please note that C = speed of light, ν = frequency, λ= wavelength, h = Planck's Constatnt

The energy of a wave that has a wavelength of 3.0 × 10⁷ nm is 6.26 × 10⁻²⁴  J 

If there is absolutely no resistance which can impede the flow or the drop of the feather and iron bar, therefore the only force that must be acting upon it is the force due to gravity. Since both objects are being accelerated by an amount of 9.81 m/s^2, therefore both objects will reach the ground together.

 

Hence the answer is:

C. both