Question

III. Label the terms 'umbra' and 'penumbra' & 'incident and reflected on
ray' in the given picture
IV. Why the word "AMBULANCE" is written backwards in an
ambulance car? Explain the phenomenon used here​

Answer 1

First Figure:

The darker portion of the shadow in the first figure is called as umbra.

The partially dark region of the shadow in the first figure is called as penumbra.

Second Figure:

The ray directed towards the reflector is the incident ray.

The ray directed away from the reflector is called reflected ray

Third Figure:

Generally the term AMBULANCE is written backward because when drivers of cars or bikes see on his view finder mirror the word gets laterally inversed and the person see the forward image of the word AMBULANCE , thus let the ambulance to overtake.