A diffraction grating is $5.0\mathrm{mm}$ wide and has $600 \mathrm{lines}$ per mm. A beam of light containing a range of wavelengths is incident on the grating. The average wavelength is $550\mathrm{nm}$. Determine the least wavelength range that can be resolved in the second order.

Explain, with the help of diagrams, the Doppler's effect. Shows clearly the cases of source that 

a. Moves towards and 

b. Goes away from a stationary observer.

A source approaches a stationary observer at  $40\mathrm{m}/\mathrm{s}$ emitting sound of frequency $500\mathrm{Hz}$. 

a. Determine the frequency the observer measure.

A source approaches a stationary observer at  $40\mathrm{m}/\mathrm{s}$ emitting sound of frequency $500\mathrm{Hz}$. 

b. Calculate the wavelength of the sound as measured by i the source and ii the observer.

A source is moving away from a stationary observer at  $32\mathrm{m}/\mathrm{s}$ emitting sound of frequency $480\mathrm{Hz}$. 

a. Determine the frequency the observer measure.

A source is moving away from a stationary observer at $32\mathrm{m}/\mathrm{s}$ emitting sound of frequency $480\mathrm{Hz}$. 

b. Calculate the wavelength of the sound as measured by i the source and ii the observer.

A sound wave of frequency $512\mathrm{Hz}$ is emitted by a stationary source towards an observer who is moving away at $12\mathrm{m}/\mathrm{s}$.

a. Determine the frequency the observer measure.

A sound wave of frequency $512\mathrm{Hz}$ is emitted by a stationary source towards an observer who is moving away at $12\mathrm{m}/\mathrm{s}$.

b. Calculate the wavelength of the sound as measured by i the source and ii the observer.