Chapter 13, Problem 10TE

To determine

The reason that the person outside the room cannot see the person inside the room.

Answer to Problem 10TE

The reflection of light from an object makes it visible to other, so the person inside the room is not visible to person outside but outside person can see the person inside.

Explanation of Solution

The perception of seeing an object depends if the light is falling on the object and it is reflecting that light too. So, if the object is not reflecting the light, then human eye can’t see the object.

The person outside the room is visible because light reflected from their surfaces reaches our eyes, while in a dark room no rays are falling inside, so no reflected light reaches our eyes and the person in the dark room is not visible.

The person in a dark room can see clearly see a person outside in the day-light because the sun rays reflected from the person outside reaches his eye, but the person in the dark room does not reflect sun rays being shielded in the dark room and is not able to be seen by the person outside.

Conclusion:

Therefore, the person insider the room is not visible to person outside but outside person can see the person inside as reflection of light rays from an object makes it visible to others.