Avehicle travels east towards a gas station. the vehicle travels a distance of 87 miles in 3 hours. what is it’s velocity

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Would it be correct to say the doppler effect is the apparent change in the speed of a wave due to the motion of the source? be sure to fully explain your position using at least 3 complete content related sentences.