Answer:
Explanation:
This type of question can be approached experimentally; so , what we are going to do here will be detailed discussion of how to go about with the experiment. So to start with;
We will need a flashlight, a flashlight holder , a protractor and a ruler.
The first step is to place the flashlight holder on a flat surface and attach
the flashlight to the holder.
From the question; the angle given is 90°
SO; we will position the flashlight at a 90° angle; by doing so , the light rays will be directed in a rectilinear position to the surface area.
To determine the angle of incidence that the main beam covered , we use a protractor to determine that.
Lastly; The surface area in cm² is determined by the use of the ruler to measure the surface area that is covered by the light rays.
Precaution: It is advisable to dim the light in the room prior to turning on the flashlight in order to avoid error due to parallax.
