Question

Which of the following real-world situations is best described as a ray?

a. The edge of a picture frame.

b. The light moving out from a lighthouse.

c. The center of a dartboard.

d.The 50 yard line of a football field.

Answer 1

In geometry, a ray is part of a line which is finite in one direction, but infinite in the other.

In optics, a ray is an idealized narrow beam of light.

Either way, looks like b

Answer 2

A ray is a line with a start but no end. Consider a sound wave. It starts, being generated by the sound generating device. But it does not have an endpoint. We may perceive it to have an endpoint, but only because our ears cannot hear the pitch.

The edge of a picture frame has a beginning and an end. That's out.

The light moving from a lighthouse has a beginning and a "perceivable" end, but in reality our eyes are just not sensitive enough to light to see the continuation, so it has no end.

The center of a dartboard. If you start from the edge and go to the center, you definitely have an endpoint, so it's not a ray.

The 50 yard line of a football field. There are endpoints at both sides of the field, so this is a line segment, which can be a portion of a ray, but is not in itself a ray.

Hope this helps. If it does, please choose good answer.
Visit my website for free math videos.
http://www.tutorsean.net