1.1. The wave equation describes the relationship between wave speed, $c$, frequency, $f$, and wavelength, $\lambda$.

UV rays travel at the speed of light and have a frequency of  $900\times{10}^{12}Hz$.

Calculate the wavelength of the UV ray in nm.

The speed of light, $c=3.00\times{10}^{8}m/s$

Use the equation

$c=f\times \lambda$

 wavelength =  .................................... nm

1.2. UV rays travel from the Sun to the Earth in 500 ms.

(i) State the relevant SI base unit for time.

(1)

(ii) Convert 500 ms into the SI base unit.

500 ms =  ............................. unit .............................(1)

1.3. A light-year is the distance that light travels in a year.

Calculate the number of seconds in one year.

Give your answer to 2 significant figures and in scientific notation.

 one year =  .................................... s

1.4. Calculate the value of 1 light-year in m.

Use your answer from part (c) to help you.

Give your answer to 2 significant figures.

The speed of light in a vacuum, $v=3.00\times{10}^{8}m/s$

 1 light-year =  .................................... m