The back of a spoon is a mirror.
a. concave
c. convex
b. complex
d. normal

The back of a spoon is bulged outward, so let us take a look at what we know from these answers:

a. concave

A concave surface is exactly what it sounds like. It is caved inward. So, no the back of a spoon is not a concave mirror.

b. convex

A convex surface is one that bulges outward, so it looks like this would suit the back of a spoon.

c. complex

A complex surface (in this case, a mirror) would be one that is made up of a multitude of smaller surfaces like the big one. There aren't a whole bunch of tiny bulges on the back of a spoon, so this is not the answer.

d. normal

A normal surface would be a flat plane, which does not suit the back of a spoon. A metal spatula maybe, but not a spoon.

The correct answer would be B. The back of a spoon is a convex mirror.
Hope that helped =)

If there was no gravity then their would be no downword force on the football to have it return the the grownd, and if there was no friction (mainly air friction) then there would be no opposing force the stop the ball from moving through the air allowing the ball to travle ∞.