A flat circular mirror of radius 0.100 m is lying on the floor. Centered directly above the mirror, at a height of 0.920 m, is a small light source. Calculate the diameter of the bright circular spot formed on the 2.70 m high ceiling by the light reflected from the mirror.

the diameter of the bright circular spot formed is 0.787 m  

Explanation:

Given that;

Radius of the flat circular mirror = 0.100 m

height of small ight source = 0.920 m

high ceiling = 2.70 m  

now;

Diameter(mirror) = 2×r = 2 × 0.100 = 0.2 m

D(spot) = [Diameter(mirror) × ( 2.70m + 0.920 m)] /  0.920 m

so

D(spot) = 0.2m × 3.62m /  0.920 m

D(spot) = 0.724 m / 0.920 m

D(spot) = 0.787 m  

Therefore, the diameter of the bright circular spot formed is 0.787 m