Question

look at the picture. who is experiencing a higher pitched sound? observer a theres no difference observer b

Explanation:

This is based on the Doppler - effect. When a source of sound (like the fire - truck) is moving towards an observer, the frequency (pitch) of the sound heard by the observer increases. Observer A is in the direction the fire - truck is moving towards, so they experience a higher - pitched sound.

Answer:

Observer A